HDU1219-1226（杭州电子科技大学第三届程序设计大赛+部分题解）

1219 水~

#include<stdio.h>
#include<string.h>
const int maxn = 30;
int a[ maxn ];
char s[ 100005 ];
int main(){
    while( gets( s )!=NULL ){
        memset( a,0,sizeof( a ) );
        int len=strlen( s );
        for( int i=0;i<len;i++ ){
            if( s[i]>='a'&&s[i]<='z' )
                a[ s[i]-'a' ]++;
        }
        for( int i=0;i<26;i++ ){
            printf("%c:%d\n",i+'a',a[i]);
        }
        printf("\n");
    }
    return 0;
}

 1222

我是找规律的。。。对于n，m，如果他们之间有公共约数，则说明在狼走第二圈的时候，会走重复的点。

#include<stdio.h>
int gcd( int a,int b ){
    int r;
    while( b ){
        r=a%b;
        a=b;
        b=r;
    }
    return a;
}
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        int n,m;
        scanf("%d%d",&m,&n);
        //while( m>n )
            //m-=n;
        if( m==1||n==1 ){
            printf("NO\n");
            continue;
        }
        if( m==n ){
            printf("YES\n");
            continue;
        }
        if( gcd(n,m)!=1 ){
            printf("YES\n");
        }
        else{
            printf("NO\n");
        }
    }
    return 0;
}            

 1224

SPFA  挺水的~~~

简单题吧

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<algorithm>
#include<queue>
#include<stack>
using namespace std;
const int maxn = 105;
const int maxm = 10000;
const int inf = 99999999;
int cnt,head[ maxn ];
struct node{
    int u,val,next;
}edge[ maxm ];
int n,m;
int val[ maxn ];
int dis[  maxn ],vis[ maxn ],path[ maxn ];

void init(){
    cnt=0;
    memset( head,-1,sizeof( head ));
}

void addedge( int a,int b,int c ){
    edge[ cnt ].u=b;
    edge[ cnt ].val=c;
    edge[ cnt ].next=head[ a ];
    head[ a ]=cnt++;
}

void bfs(){
    for( int i=1;i<=n+1;i++ ){
        vis[i]=0;
        dis[i]=-inf;
        path[i]=-1;
    }
    queue<int>q;
    while( !q.empty() )
        q.pop();
    q.push( 1 );
    vis[1]=1;
    dis[1]=0;
    while( !q.empty() ){
        int now=q.front();
        q.pop();
        vis[ now ]=0;
        for( int i=head[ now ];i!=-1;i=edge[ i ].next ){
            int next=edge[i].u;
            if( dis[next]<dis[now]+val[next] ){
                dis[next]=dis[now]+val[next];
                path[next]=now;
                if( vis[next]==0 ){
                    vis[next]=1;
                    q.push(next);
                }
            }
        }
    }
}
void output(){
    printf("points : %d\n",dis[n+1]);
    stack<int>s;
    for( int i=n+1;i!=-1;i=path[i] ){
        s.push( i );
    }
    printf("circuit : ");
    printf("%d",s.top());
    s.pop();
    while( !s.empty() ){
        if( s.top()==(n+1) )
            printf("->%d",1);
        else
            printf("->%d",s.top());
        s.pop();
    }
    printf("\n");
}
int main(){
    int T;
    scanf("%d",&T);
    for( int ca=1;ca<=T;ca++ ){
        if( ca!=1 )
            printf("\n");
        scanf("%d",&n);
        for( int i=1;i<=n;i++ )
            scanf("%d",&val[ i ]);
        val[n+1]=0;
        scanf("%d",&m);
        int a,b;
        init();
        while( m-- ){
            scanf("%d%d",&a,&b);
            if( a<b ){
                addedge( a,b,0 );
            }
            else if( a>b ){
                addedge( b,a,0 );
            }
        }
        bfs();
        printf("CASE %d#\n",ca);
        //printf("%d\n",dis[n+1]);
        output();
    }
    return 0;
}

 1225

字符串的水题~~~

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
const int maxn = 5005;
struct node{
    char name[ 105 ];
    int win,lost,diff,score;
}team[ maxn ];
int cnt;
void init( int n ){
    for( int i=0;i<=n;i++ ){
        team[ i ].win=team[ i ].lost=team[ i ].diff=team[ i ].score=0;
        //memset( team[i].name,'\0',sizeof( team[i].name ));
    }
    cnt=0;
}
int find( char tt[] ){
    if( cnt==0 ){
        strcpy( team[0].name,tt );
        cnt++;
        return 0;
    }
    int i;
    for( i=0;i<cnt;i++ ){
        if( strcmp( tt,team[i].name )==0 ){
            return i;
        }
    }
    if( i==cnt ){
        strcpy( team[cnt].name,tt );
        cnt++;
        return cnt-1;
    }
}
bool cmp( node a,node b ){
    if( a.score!=b.score )
        return a.score>b.score;
    else if( a.diff!=b.diff )
        return a.diff>b.diff;
    else if( a.win!=b.win )
        return a.win>b.win;
    else if( strcmp( a.name,b.name )>0 )
        return false;
    else return true;
}
int main(){
    int n;
    while( scanf("%d",&n)!=EOF ){
        init( n );
        char n1[ 105 ],n2[ 105 ];
        int num1,num2;
        for( int i=0;i<(n*(n-1));i++ ){
            scanf("%s VS %s %d:%d",n1,n2,&num1,&num2);
            int f1=find( n1 );
            int f2=find( n2 );
            if( num1==num2 ){
                team[ f1 ].score++;
                team[ f2 ].score++;
                team[ f1 ].win+=num1;
                team[ f1 ].lost+=num1;
                team[ f2 ].win+=num2;
                team[ f2 ].lost+=num2;
            }
            else if( num1>num2 ){
                team[ f1 ].win+=num1;
                team[ f1 ].lost+=num2;
                team[ f2 ].win+=num2;
                team[ f2 ].lost+=num1;
                team[ f1 ].score+=3;
            }
            else if( num1<num2 ){
                team[ f1 ].win+=num1;
                team[ f1 ].lost+=num2;
                team[ f2 ].win+=num2;
                team[ f2 ].lost+=num1;
                team[ f2 ].score+=3;
            }
        }
        for( int i=0;i<n;i++ ){
            team[ i ].diff=team[ i ].win-team[ i ].lost;
        }
        sort( team,team+n,cmp );
        for( int i=0;i<n;i++ ){
            printf("%s %d\n",team[i].name,team[i].score);
        }
        printf("\n");
    }
    return 0;
}

 1226

BFS+5000个状态+mod！！！

#include<stdio.h>
#include<stdlib.h>
#include<string>
#include<algorithm>
#include<math.h>
#include<iostream>
#include<queue>
using namespace std;
const int maxn = 24;
const int maxm = 5105;
const int inf = 99999999;
int n,m,c;
int a[ maxn ];
int vis[ maxm ];
int flag;
struct node{
    string ans;
    int mod;
};
string res;
queue<node>q;
void init2(){
    while( !q.empty() )
        q.pop();
}
void init1(){
    memset( a,0,sizeof( a ));
    memset( vis,0,sizeof( vis ));
    flag=-1;
    res.clear();
}
void bfs(){
    init2();
    node now,next;
    for( int i=1;i<16;i++ ){
        if( a[i] ){
            vis[ i%n ]=1;
            if( i>=0&&i<=9 ){
                now.ans="";
                now.ans=(i+'0');
                now.mod=i%n;
                q.push( now );
            }
            else{
                now.ans="";
                now.ans=(i+'A'-10);
                now.mod=i%n;
                q.push( now );
            }
        }
    }//the init
    while( !q.empty() ){
        now=q.front(),q.pop();
        if( flag==1&&now.ans.size()>res.size() )
            continue;
        if( now.mod==0 ){
            if( flag==-1 ){
                flag=1;
                res=now.ans;
            }
            else{
                if( now.ans.size()<res.size() ){
                    res=now.ans;
                }
                else if( now.ans.size()==res.size()&&res>now.ans ){
                    res=now.ans;
                }
            }
        }
        for( int i=0;i<16;i++ ){
            if( a[i] ){
                if( i<10 ){
                    next=now;
                    next.ans+=( i+'0' );
                    next.mod=(now.mod*c+i)%n;
                    if( ( next.ans.size()<=500&&vis[ next.mod ]==0 )||( next.mod==0 ) ){
                        vis[ next.mod ]=1;
                        q.push( next );
                    }
                }
                else{
                    next=now;
                    next.ans+=(i+'A'-10);
                    next.mod=(now.mod*c+i)%n;
                    if( ( next.ans.size()<=500&&vis[ next.mod ]==0 )||( next.mod==0 ) ){
                        vis[ next.mod ]=1;
                        q.push( next );
                    }
                }
            }
        }
    }
}

int main(){
    int ca;
    scanf("%d",&ca);
    while( ca-- ){
        scanf("%d%d%d",&n,&c,&m);
        init1();
        char ch[ 4 ];
        for( int i=0;i<m;i++ ){
            scanf("%s",ch);
            if( ch[0]>='0'&&ch[0]<='9' )
                a[ ch[0]-'0' ]=1;
            else
                a[ ch[0]-'A'+10 ]=1;
        }
         if(n==0){  
           // cout<<0<<endl;  
            if(a[0]==1)  
                cout<<0<<endl;  
            else  
                cout<<"give me the bomb please"<<endl;  
            continue;  
        }  
        bfs();
        if( flag==-1 )
            printf("give me the bomb please\n");
        else
            cout<<res<<endl;
    }
    return 0;
}