NYOJ 284

法一：

#include<iostream>#include<cstdio>#include<queue>using namespace std;typedef struct node{    int x,y,step;}node;bool operator<(const node &a,const node &b){    return a.step>b.step;}int dir[4][2]={{0,1},{0,-1},{1,0},{-1,0}};int main(){    char map[305][305];    int i,j,ans,n,m;    node a,b;    priority_queue<node>q;    while(scanf("%d %d",&n,&m)&&(n||m))    {        a.x=0;        for(i=0;i<n;i++)        {            scanf("%s*c",&map[i]);            for(j=0;j<m;j++)            {                if(map[i][j]=='Y')                {                    a.x=i;                    a.y=j;                    a.step=0;                    q.push(a);                }            }        }        bool flag=false;        while(!q.empty())//广搜        {            a=q.top();            q.pop();            for(i=0;i<4;i++)            {                b.x=a.x+dir[i][0];                b.y=a.y+dir[i][1];                if(b.x>=0 && b.x<n && b.y>=0 && b.y<m)                {                    if(map[b.x][b.y]=='T')                    {                        ans=a.step+1;                        flag=true;                        break;                    }                    else if(map[b.x][b.y]=='E')                    {                        b.step=a.step+1;                        q.push(b);                        map[b.x][b.y]='S';                    }                    else if(map[b.x][b.y]=='B')                    {                        b.step=a.step+2;                        q.push(b);                        map[b.x][b.y]='S';                    }                }            }            if(flag)                break;        }        if(flag)            printf("%d\n",ans);        else            printf("-1\n");        while(!q.empty())        {            q.pop();        }    }    return 0;}

法二：

#include <cstdio>#include <cstring>#include <queue>using namespace std;int m, n;struct node{    int x, y;    node(int a, int b){        x = a; y = b;    }}*xm, *d;char maze[301][301];int dist[301][301], steps;bool vis[301][301];queue<node*> q;void PUSH(int a, int b){    if(vis[a][b] || a < 1 || b < 1 || a > m || b > n || maze[a][b] == 'S' || maze[a][b] == 'R') return;    q.push(new node(a, b));    dist[a][b] = steps+1;    vis[a][b] = 1;}int bfs(){    memset(vis, 0, sizeof(vis));    memset(dist, 0, sizeof(dist));    node *cur = new node(xm->x, xm->y);    while(!q.empty()) q.pop();    q.push(cur);    vis[xm->x][xm->y] = 1;    while(!q.empty()){        cur = q.front(); q.pop();        steps = dist[cur->x][cur->y];        if(cur->x == d->x && cur->y == d->y)            return dist[d->x][d->y];        if(maze[cur->x][cur->y] == 'B'){            maze[cur->x][cur->y] = 'E';            vis[cur->x][cur->y] = 0;            PUSH(cur->x, cur->y);        }else if(maze[cur->x][cur->y] != 'R' || maze[cur->x][cur->y] != 'S'){            PUSH(cur->x - 1, cur->y);            PUSH(cur->x, cur->y - 1);            PUSH(cur->x, cur->y + 1);            PUSH(cur->x + 1, cur->y);        }    }    return -1;}int main(){    int i, j;    while(scanf("%d%d", &m, &n) && m||n){        for(i = 1; i <= m; i++)            for(j = 1; j <= n; j++){                scanf(" %c ", &maze[i][j]);                if(maze[i][j] == 'Y')                    xm = new node(i, j);                else if(maze[i][j] == 'T')                    d = new node(i, j);            }        printf("%d\n", bfs());    }    return 0;}

priority_queue

#include<iostream>#include<functional>#include<queue>#include<vector>using namespace std;//定义比较结构struct cmp1{    bool operator ()(int &a,int &b){        return a>b;//最小值优先    }};struct cmp2{    bool operator ()(int &a,int &b){        return a<b;//最大值优先    }};//自定义数据结构struct number1{    int x;    bool operator < (const number1 &a) const {        return x>a.x;//最小值优先    }};struct number2{    int x;    bool operator < (const number2 &a) const {        return x<a.x;//最大值优先    }};int a[]={14,10,56,7,83,22,36,91,3,47,72,0};number1 num1[]={14,10,56,7,83,22,36,91,3,47,72,0};number2 num2[]={14,10,56,7,83,22,36,91,3,47,72,0};int main(){    priority_queue<int>que;//采用默认优先级构造队列    priority_queue<int,vector<int>,cmp1>que1;//最小值优先    priority_queue<int,vector<int>,cmp2>que2;//最大值优先    priority_queue<int,vector<int>,greater<int> >que3;//注意“>>”会被认为错误，    priority_queue<int,vector<int>,less<int> >que4;////最大值优先    priority_queue<number1>que5; //最小优先级队列    priority_queue<number2>que6;  //最大优先级队列    int i;    for(i=0;a[i];i++){        que.push(a[i]);        que1.push(a[i]);        que2.push(a[i]);        que3.push(a[i]);        que4.push(a[i]);    }    for(i=0;num1[i].x;i++)        que5.push(num1[i]);    for(i=0;num2[i].x;i++)        que6.push(num2[i]);    printf("采用默认优先关系:/n(priority_queue<int>que;)/n");    printf("Queue 0:/n");    while(!que.empty()){        printf("%3d",que.top());        que.pop();    }    puts("");    puts("");    printf("采用结构体自定义优先级方式一:/n(priority_queue<int,vector<int>,cmp>que;)/n");    printf("Queue 1:/n");    while(!que1.empty()){        printf("%3d",que1.top());        que1.pop();    }    puts("");    printf("Queue 2:/n");    while(!que2.empty()){        printf("%3d",que2.top());        que2.pop();    }    puts("");    puts("");    printf("采用头文件/"functional/"内定义优先级:/n(priority_queue<int,vector<int>,greater<int>/less<int> >que;)/n");    printf("Queue 3:/n");    while(!que3.empty()){        printf("%3d",que3.top());        que3.pop();    }    puts("");    printf("Queue 4:/n");    while(!que4.empty()){        printf("%3d",que4.top());        que4.pop();    }    puts("");    puts("");    printf("采用结构体自定义优先级方式二:/n(priority_queue<number>que)/n");    printf("Queue 5:/n");    while(!que5.empty()){        printf("%3d",que5.top());        que5.pop();    }    puts("");    printf("Queue 6:/n");    while(!que6.empty()){        printf("%3d",que6.top());        que6.pop();    }    puts("");    return 0;}/*运行结果 ：采用默认优先关系:(priority_queue<int>que;)Queue 0:83 72 56 47 36 22 14 10  7  3采用结构体自定义优先级方式一:(priority_queue<int,vector<int>,cmp>que;)Queue 1: 7 10 14 22 36 47 56 72 83 91Queue 2:83 72 56 47 36 22 14 10  7  3采用头文件"functional"内定义优先级:(priority_queue<int,vector<int>,greater<int>/less<int> >que;)Queue 3: 7 10 14 22 36 47 56 72 83 91Queue 4:83 72 56 47 36 22 14 10  7  3采用结构体自定义优先级方式二:(priority_queue<number>que)Queue 5: 7 10 14 22 36 47 56 72 83 91Queue 6:83 72 56 47 36 22 14 10  7  3*/

法三：

#include <iostream> #include <queue> #include <cstdio> #include <cstring> using namespace std; #define  max 301 char map[max][max]; int n,m; bool vist[max][max]; int d[4][2]={{1,0},{0,1},{-1,0},{0,-1}}; struct node {     int x,y,c;     friend bool operator <(const node &s1,const node &s2)     {         return s1.c>s2.c;     } }; node s,e; int bfs() {     priority_queue < node > q;     memset(vist,0,sizeof(vist));     node now,t;     s.c=0;     q.push(s);     vist[s.x][s.y]=1;     while (!q.empty())     {         now=q.top();         q.pop();         if (now.x==e.x&&now.y==e.y)         {             return now.c;         }         for (int i=0;i<4;i++)         {             t.x=now.x+d[i][0];             t.y=now.y+d[i][1];             if (t.x>=0&&t.x<n&&t.y>=0&&t.y<m&&!vist[t.x][t.y])             {                 vist[t.x][t.y]=1;                 if (map[t.x][t.y]=='B')                 {                     t.c=now.c+2;                     q.push(t);                 }                 else                     if (map[t.x][t.y]=='E'||map[t.x][t.y]=='T')                     {                         t.c=now.c+1;                         q.push(t);                     }             }         }     }     return -1; } int main() {     int i,j;     while (cin>>n>>m,m+n)     {         for (i=0;i<n;i++)         {             for (j=0;j<m;j++)             {                 cin>>map[i][j];                 if (map[i][j]=='Y')                     s.x=i,s.y=j;                 if (map[i][j]=='T')                     e.x=i,e.y=j;             }         }         int sum=bfs();      cout<<sum<<endl;     }     return 0; }