USACO 合集

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第一篇这个站上的博客，总结USACO的程序
总结一下思路

USACO1.1

  • Your Ride Is Here

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    #include<cstdio>
    #include<cstring>
    using namespace std;
    char a[10],b[10];
    int main(){
        int i,j,k,n=1,m=1,l1,l2;
        scanf("%s%s",&a,&b);
        l1=strlen(a);
        l2=strlen(b);
        for(i=0;i<l1;i++){
            n*=a[i]-'A'+1;
            n%=47;
        }
        for(i=0;i<l2;i++){
            m*=(int)b[i]-'A'+1;
            m%=47;
        }
        if(n==m) printf("GO\n");
        else printf("STAY\n");
        return 0;
    }

  • Greedy Gift Givers

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<algorithm>
    #include<iostream>
    using namespace std;
    const int maxn=10+10,maxl=14+10;
    char s[maxn][maxl],c[maxl];
    int a[maxn];
    int main(){
        int i,j,k,n,m;
        int x,y;
        scanf("%d",&n);
        for(i=1;i<=n;i++)
            scanf("%s",s[i]);
        while(scanf("%s%d%d",c,&x,&y)!=EOF){
            if(y==0) continue;
            for(i=1;i<=n;i++)
                if(!strcmp(c,s[i]))
                    a[i]+=(x/y)*y;
            for(i=1;i<=y;i++){
                scanf("%s",c);
                for(j=1;j<=n;j++)
                    if(!strcmp(c,s[j]))
                        a[j]-=x/y;
            }
        }
        for(i=1;i<=n;i++)
            printf("%s %d\n",s[i],-1*a[i]);
        return 0;
    }

  • Friday the Thirteenth

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    #include<cstdio>
    #include<cstdlib>
    #include<cmath>
    #include<cstring>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    bool pd(int x){
        return x%400==0 || (x%100!=0 && x%4==0);
    }
    int ans[7];
    int main(){
        int i,j,k=13,n,m;
        scanf("%d",&n);
        for(i=1900;i<1900+n;i++)
            for(j=1;j<=12;j++){
                k%=7;
                ans[k]++;
                if(j==2){
                    if(pd(i)) k+=29;
                    else k+=28;
                }
                else if(j==4 || j==6 || j==9 || j==11) k+=30;
                else k+=31;
            }
        printf("%d %d ",ans[6],ans[0]);
        for(i=1;i<=5;i++)
            printf("%d ",ans[i]);
        
        return 0;
    }

  • Broken Necklace

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=350*2+10;
    int a[maxn],ls,rs;
    int main(){
        int i,j,k,k1,n,m;
        scanf("%d",&n);
        char s[maxn],c;
        scanf("%s",s);
        for(i=1;i<=n;i++){
            c=s[i-1];
            if(c=='r') a[i]=a[i+n]=1;
            if(c=='b') a[i]=a[i+n]=2;
            if(c=='w') a[i]=a[i+n]=3;
        }
        int Max=0;
        m=n*2;
        for(i=1;i<=m;i++){
            if(k1==3) ls++,k1=a[i];
            else if(ls==0) ls=1,k1=a[i];
            else if(k1==a[i] || a[i]==3) ls++;
            else{
                ls=1,k1=a[i];
                j=i-1;
                while(a[j]==3) j--,ls++;
            }
            rs--;
            if(rs<1){
                rs=1;
                j=i+1;
                while(a[j]==3) j++,rs++;
                k=j+1;
                while((a[j]==a[k] || a[k]==3) && j+1<=m) k++,rs++;
            }
            if(ls+rs>Max){
                Max=ls+rs;
            }
            if(Max>=n){
                printf("%d\n",n);
                return 0;
            }
        }
        printf("%d\n",Max);
        return 0;
    }

USACO1.2

  • Milking Cows

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    #include<cstdio>
    #include<cstdlib>
    #include<cmath>
    #include<cstring>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=5000+10;
    struct point{
        int s,t;
    }a[maxn];
    bool cmp(point A,point B){
        return A.s<B.s;
    }
    int x,y;
    int Maxlast,Maxfree;
    int main(){
        int i,j,k,n,m;
        scanf("%d",&n);
        for(i=1;i<=n;i++)
            scanf("%d%d",&a[i].s,&a[i].t);
        sort(a+1,a+n+1,cmp);
        x=a[1].s;
        y=a[1].t;
        Maxlast=max(Maxlast,y-x);
        for(i=2;i<=n;i++){
            if(a[i].s<=y){
                if(a[i].t>y) y=a[i].t;
            }
            else{
                Maxfree=max(Maxfree,a[i].s-y);
                x=a[i].s;
                y=a[i].t;
            }
            Maxlast=max(Maxlast,y-x);
        }
        printf("%d %d\n",Maxlast,Maxfree);
        return 0;
    }

  • Transformations

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    char n,a[11][11],b[11][11],c[11][11];
    bool pd(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                if(b[i][j]!=c[i][j])
                    return false;
        return true;
    }
    void work1(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                b[j][n-i+1]=a[i][j];
    }
    void work2(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                b[n-i+1][n-j+1]=a[i][j];
    }
    void work3(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                b[n-j+1][i]=a[i][j];
    }
    void work4(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                b[i][n-j+1]=a[i][j];
    }
    void work6(){
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                b[i][j]=a[i][j];
    }
    void work5(){
        work4();
        int i,j;
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                a[i][j]=b[i][j];
    }
    int main(){
        int i,j,k,m;
        scanf("%d",&n);
        for(i=1;i<=n;i++)
            scanf("%s",a[i]+1);
        for(i=1;i<=n;i++)
            scanf("%s",c[i]+1);
        work1();
        if(pd()){
            puts("1");
            return 0;
        }
        work2();
        if(pd()){
            puts("2");
            return 0;
        }
        work3();
        if(pd()){
            puts("3");
            return 0;
        }
        work4();
        if(pd()){
            puts("4");
            return 0;
        }
        work6();
        if(pd()){
            puts("6");
            return 0;
        }
        work5();
        work1();
        if(pd()){
            puts("5");
            return 0;
        }
        work2();
        if(pd()){
            puts("5");
            return 0;
        }
        work3();
        if(pd()){
            puts("5");
            return 0;
        }
        puts("7");
        return 0;
    }

  • Palindromic Squares

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    #include<cstdio>
    #include<cstdlib>
    #include<cmath>
    #include<cstring>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    int n;
    int a[100+10],b[100+10],alen=0,blen=0;
    bool pd(){
        int i;
        for(i=1;i<=blen/2;i++)
            if(b[i]!=b[blen-i+1])
                return false;
        return true;
    }
    void out(){
        int i;
        for(i=alen;i>=1;i--)
            if(a[i]>=10) printf("%c",a[i]-10+'A');
            else printf("%d",a[i]);
        putchar(' ');
        for(i=blen;i>=1;i--)
            if(b[i]>=10) printf("%c",b[i]-10+'A');
            else printf("%d",b[i]);
        putchar('\n');
    }
    void work(int x){
        int i,j,k=x*x;
        int y=x;
        alen=0;
        blen=0;
        while(y>0){
            a[++alen]=y%n;
            y/=n;
        }
        while(k>0){
            b[++blen]=k%n;
            k/=n;
        }
        if(!pd()) return;
        out();
    }
    int main(){
        int i,j,k,m;
        scanf("%d",&n);
        for(i=1;i<=300;i++)
            work(i);
        return 0;
    }

  • Dual Palindromes

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    #include<cstdio>
    #include<cstdlib>
    #include<cmath>
    #include<cstring>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    int n;
    int b[100+10],blen=0;
    bool pd(){
    	int i;
    	for(i=1;i<=blen/2;i++)
    		if(b[i]!=b[blen-i+1])
    			return false;
    	return true;
    }
    bool work(int x,int y){
    	int i,j,k=x;
    	blen=0;
    	while(k>0){
    		b[++blen]=k%y;
    		k/=y;
    	}
    	return pd();
    }
    int main(){
    	int i,j,k,m;
    	scanf("%d%d",&n,&m);
    	int sum=0;
    	for(i=m+1;sum<n;i++){
    		int num=0;
    		for(j=2;j<=10;j++)
    			if(work(i,j)) num++;
    		if(num>=2){
    			printf("%d\n",i);
    			sum++;
    		}
    	}
    	return 0;
    }

USACO1.3

  • Mixing Milk

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=5000+10;
    struct point{
        int x,y;
    }a[maxn];
    bool cmp(point A,point B){
        return A.x<B.x;
    }
    int main(){
        int i,j,k,n,m;
        scanf("%d%d",&n,&m);
        for(i=1;i<=m;i++)
            scanf("%d%d",&a[i].x,&a[i].y);
        sort(a+1,a+m+1,cmp);
        i=0;
        int ans=0;
        while(1){
            i++;
            if(n<=a[i].y){
                ans+=a[i].x*n;
                break;
            }
            else{
                ans+=a[i].x*a[i].y;
                n-=a[i].y;
            }
        }
        printf("%d\n",ans);
        return 0;
    }

  • Barn Repair

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=200+10;
    int a[maxn],k[maxn];
    int main(){
        int i,j,n,m;
        int s,c;
        int last;
        scanf("%d%d%d",&m,&s,&c);
        for(i=1;i<=c;i++)
            scanf("%d",&k[i]);
        sort(k+1,k+c+1);
        last=k[1];
        for(i=2;i<=c;i++){
            a[i-1]=k[i]-last-1;
            last=k[i];
        }
        sort(a+1,a+c);
        int ans=c;
        for(i=1;i<=c-m;i++)
            ans+=a[i];
        printf("%d\n",ans);
        return 0;
    }

  • Prime Cryptarithm

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    bool p[10];
    int num[10],ans;
    bool pd(int x){
        while(x>0){
            if(!p[x%10]) return false;
            x/=10;
        }
        return true;
    }
    int sw(int x){
        int sum=0;
        while(x>0){
            sum++;
            x/=10;
        }
        return sum;
    }
    int main(){
        int i,j,k,n,m;
        scanf("%d",&n);
        for(i=1;i<=n;i++){
            scanf("%d",&num[i]);
            p[num[i]]=true;
        }
        int a,b,c,d,e;
        int x,y;
        for(a=1;a<=n;a++)
            for(b=1;b<=n;b++)
                for(c=1;c<=n;c++){
                    x=num[a]*100+num[b]*10+num[c];
                    for(d=1;d<=n;d++)
                        if(pd(x*num[d]) && sw(x*num[d])==3)
                            for(e=1;e<=n;e++)
                                if(pd(x*num[e]) && pd(x*(num[d]*10+num[e])) && sw(x*num[e])==3 && sw(x*(num[d]*10+num[e]))==4){
                                    ans++;
                                }
                }
        printf("%d\n",ans);
        return 0;
    }

  • wormhole

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=12+10;
    #define next Next
    struct point{
        int x,y;
    }a[maxn];
    int n,next[maxn],part[maxn];
    bool cmp(point A,point B){
        return A.y<B.y || (A.y==B.y && A.x<B.x);
    }
    bool pd(){
        int i,j,tmp;
        for(i=1;i<=n;i++){
            tmp=i;
            for(j=1;j<=n;j++)
                tmp=next[part[tmp]];
            if(tmp!=0) return true;
        }
        return false;
    }
    int dfs(){
        int tot=0,i;
        for(i=1;i<=n;i++)
            if(part[i]==0)
                break;
        if(i>n){
            if(pd()) return 1;
            return 0;
        }
        int j;
        for(j=i+1;j<=n;j++)
            if(part[j]==0){
                part[j]=i;
                part[i]=j;
                tot+=dfs();
                part[i]=0;
                part[j]=0;
            }
        return tot;
    }
    int main(){
        int i,j,k,m;
        scanf("%d",&n);
        for(i=1;i<=n;i++)
            scanf("%d%d",&a[i].x,&a[i].y);
        sort(a+1,a+n+1,cmp);
        int sum=0;
        for(i=1;i<=n-1;i++)
            if(a[i].x<a[i+1].x && a[i].y==a[i+1].y)
                next[i]=i+1;
        printf("%d\n",dfs());
        return 0;
    }

  • Ski Course Design

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=1000+10,inf=1e9;
    int a[maxn];
    int main(){
        int i,j,k,n,m;
        scanf("%d",&n);
        for(i=1;i<=n;i++)
            scanf("%d",&a[i]);
        sort(a+1,a+n+1);
        int Min=inf;
        for(i=a[1];i<=a[n]-17;i++){
            int tmp=0;
            j=1;
            while(a[j]<i){
                tmp+=(i-a[j])*(i-a[j]);
                j++;
            }
            j=n;
            while(a[j]-i>17){
                tmp+=(a[j]-i-17)*(a[j]-i-17);
                j--;
            }
            Min=min(tmp,Min);
        }
        printf("%d\n",Min);
        return 0;
    }

  • Combination Lock

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=100+1;
    bool p[maxn][maxn][maxn];
    int main(){
    	int i,j,k,n,m;
    	int sum=0;
    	int x,y,z;
    	scanf("%d",&n);
    	scanf("%d%d%d",&x,&y,&z);
    	for(i=-2;i<=2;i++)
    		for(j=-2;j<=2;j++)
    			for(k=-2;k<=2;k++)
    				p[(x+n+i)%n][(y+n+j)%n][(z+n+k)%n]=1;
    	scanf("%d%d%d",&x,&y,&z);
    	for(i=-2;i<=2;i++)
    		for(j=-2;j<=2;j++)
    			for(k=-2;k<=2;k++)
    				p[(x+n+i)%n][(y+n+j)%n][(z+n+k)%n]=1;
    	for(i=0;i<n;i++)
    		for(j=0;j<n;j++)
    			for(k=0;k<n;k++)
    				if(p[i][j][k])
    					sum++;
    	printf("%d\n",sum);
    	return 0;
    }

USACO1.4

  • Arithmetic Progressions

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxm=250,maxn=25+1;
    bool p[maxm*maxm*2+1];
    bool vis;
    int n,m,Max,tmp,a[maxm*maxm*2+1];
    void work(){
    	int i,j;
    	for(i=0;i<=m;i++)
    		for(j=0;j<=m;j++){
    			p[i*i+j*j]=1;
    			if(i*i+j*j>Max) Max=i*i+j*j;
    		}
    	for(i=0;i<=Max;i++)
    		if(p[i])
    			a[++tmp]=i;
    	return;
    }
    int main(){
    	int i,j,k;
    	scanf("%d%d",&n,&m);
    	int a1,b;
    	work();
    	sort(a+1,a+n+1);
    	for(b=1;b<=Max;b++)
    		for(a1=1;a1<=tmp && b*(n-1)+a[a1]<=Max;a1++){
    				for(k=1;k<n;k++)
    					if(!p[a[a1]+b*k])
    						break;
    				if(k==n){
    					printf("%d %d\n",a[a1],b);
    					vis=1;
    				}
    			}
    	if(!vis) puts("NONE");
    	return 0;
    }

  • Mother’s Milk

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    #include<cstdio>
    #include<cstring>
    #include<cmath>
    #include<cstdlib>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=20+10;
    int vis[maxn][maxn],p[maxn];
    int max_a,max_b,max_c;
    void dfs(int x,int y,int z){
    	if(x>max_a || y>max_b || z>max_c) return;
    	if(x<0 || y<0 || z<0) return;
    	if(vis[x][y]) return;
    	vis[x][y]=1;
    	if(x==0) p[z]=1;
    	dfs(0,y+x,z);
    	dfs(0,y,z+x);
    	dfs(x-max_b+y,max_b,z);
    	dfs(x-max_c+z,y,max_c);
    	dfs(x+y,0,z);
    	dfs(x,0,y+z);
    	dfs(max_a,y-max_a+x,z);
    	dfs(x,y-max_c+z,max_c);
    	dfs(x+z,y,0);
    	dfs(x,z+y,0);
    	dfs(max_a,y,z-max_a+x);
    	dfs(x,max_b,z-max_b+y);
    }
    int main(){
    	int i,j,k,n,m;
    	scanf("%d%d%d",&max_a,&max_b,&max_c);
    	dfs(0,0,max_c);
    	for(i=0;i<=20;i++)
    		if(p[i])
    			printf("%d ",i);
    	putchar('\n');
    	return 0;
    }

USACO1.5

  • Number Triangles

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    #include<cstdio>
    #include<cstring>
    #include<cmath>
    #include<cstdlib>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=1001,inf=-1e9;
    int f[maxn*maxn];
    int main(){
    	int i,j,k,n,m;
    	scanf("%d",&n);
    	for(i=1;i<=n*(n-1)/2;i++)
    		f[i]=inf;
    	for(i=1;i<=n;i++)
    		for(j=i*(i-1)/2+1;j<=i*(i+1)/2;j++){
    			scanf("%d",&k);
    			if(i==1) f[j]=k;
    			if(j!=1) f[j]=max(f[j],k+f[j-i]);
    			if(j!=i*(i+1)/2) f[j]=max(f[j],k+f[j-i+1]);
    		}
    	int Max=inf;
    	for(i=n*(n-1)/2+1;i<=n*(n+1);i++)
    		Max=max(Max,f[i]);
    	printf("%d\n",Max);
    	return 0;
    }

  • Prime Palindromes

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    #include<cstdio>
    #include<cstdlib>
    #include<cstring>
    #include<cmath>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    const int maxn=1000000+10;
    int a[11],num,n,m;
    int ans[maxn],tmp;
    void pd(){
    	int i,sum=0;
    	for(i=1;i<=(num+1)/2;i++)
    		sum=sum*10+a[i];
    	for(i=num/2;i>=1;i--)
    		sum=sum*10+a[i];
    	int x=(int)sqrt(sum);
    	if(sum<n) return;
    	if(sum>m) return;
    	for(i=2;i<=x;i++)
    		if(sum%i==0)
    			return;
    	ans[++tmp]=sum;
    }
    void work(int x){
    	int i;
    	if(x==0){
    		pd();
    		return;
    	}
    	for(i=0;i<=9;i++){
    		a[x]=i;
    		work(x-1);
    	}
    }
    int main(){
    	int i,j,k;
    	scanf("%d%d",&n,&m);
    	if(n<=2) puts("2");
    	int x=n,y=m,xsum=0,ysum=0;
    	while(x>0){
    		x/=10;
    		xsum++;
    	}
    	while(y>0){
    		y/=10;
    		ysum++;
    	}
    	for(i=xsum;i<=ysum;i++){
    		num=i;
    		work((i+1)/2);
    	}
    	sort(ans+1,ans+tmp+1);
    	for(i=1;i<=tmp;i++)
    		printf("%d\n",ans[i]);
    	return 0;
    }

  • Superprime Rib

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    #include<cstdio>
    #include<cstring>
    #include<cmath>
    #include<cstdlib>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    int a[4]={2,3,5,7},sum=0;
    bool pd(){
    	int i;
    	int x=(int)sqrt(sum);
    	for(i=2;i<=x;i++)
    		if(sum%i==0)
    			return false;
    	return true;
    }
    void dfs(int x){
    	int i;
    	if(!pd()) return;
    	if(x==0) printf("%d\n",sum);
    	for(i=1;i<=9;i+=2){
    		sum=sum*10+i;
    		dfs(x-1);
    		sum/=10;
    	}
    }
    int main(){
    	int i,j,k,n,m;
    	scanf("%d",&n);
    	for(i=0;i<4;i++){
    		sum=a[i];
    		dfs(n-1);
    	}
    	return 0;
    }

USACO2.1

USACO2.2

USACO2.3

USACO2.4

USACO3.1

USACO3.2

USACO3.3

USACO3.4

USACO4.1

USACO4.2

USACO4.3

USACO4.4

USACO5.1

USACO5.2

USACO5.3

USACO5.4

USACO5.5