上海金马五校程序设计竞赛 Problem B : Sailing

题目链接 http://acm.dhu.edu.cn/contest/view.html?id=875&index=1

优先队列，步数相同的，*号优先

#include<stdio.h>#include<time.h>#include<cmath>#include <iostream>#include<string.h>#include <set>#include <queue>using namespace std;typedef long long  ll;const int maxn = 21;char a[55][55];class Node{    public :    int x;int y;int d;    Node(int a, int b, int c):x(a),y(b),d(c){}};bool operator < (const Node &t1, const Node&t2){    return t1.d > t2.d||(t1.d==t2.d&&((a[t1.x][t1.y]==a[t2.x][t2.y])||(a[t1.x][t1.y]=='#'&&a[t2.x][t2.y]=='*'))); // 按照z的顺序来决定t1和t2的顺序}    int dx[4]={-1,0,1,0};int dy[4]={0,-1,0,1};int res[55][55];int main(){    int n;    priority_queue<Node> q;    while(scanf("%d",&n)!=EOF){        memset(res, 0, sizeof(res));//        cout<<n<<endl;        while(!q.empty()){            q.pop();        }        for(int i=0;i<n;i++)            for(int j=0;j<n;j++){                cin>>a[i][j];        }//        for(int i=0;i<n;i++)//            for(int j=0;j<n;j++){//                cout<<a[i][j];//            }        q.push(Node(0,0,0));        res[0][0] = 1;        int tx,ty,td;        while (!q.empty()){            Node t = q.top();            q.pop();//            cout<<t.x<<" "<<t.y<<" "<<t.d<<endl;            if(t.x==n-1&&t.y==n-1){                cout<<t.d<<endl;break;            }            for(int i=0;i<4;i++){                tx = t.x+dx[i];                ty = t.y+dy[i];                td = t.d;                if(res[tx][ty]==0&&tx>=0&&ty>=0&&tx<n&&ty<n){                    res[tx][ty]=1;                    if(a[t.x][t.y]=='#'||a[tx][ty]=='#')                        td++;                    q.push(Node(tx,ty,td));//                    cout<<tx<<" "<<ty<<" "<<td<<endl;                }            }        }    }    return 0;}