1321. Robot （dijkstra）

#include <iostream> //優先順序隊列實現dijkstra演算法很方便#include <cstring>#include <queue>using namespace std;class Path{public:    int i, j;    int dist;    Path( int a, int b, int c ) { i = a; j = b; dist = c; }    friend bool operator<(const Path &p1,const Path &p2 )//反向規定使得top變為最小值{return p1.dist > p2.dist; }};int dirt[4][2]={{-1,0},{0,1},{1,0},{0,-1}};int main(){    int T,row,column,si,sj,ti,tj,i,j,k,grid[101][101];    bool included[ 101 ][ 101 ];    cin>>T;    while(T--){        priority_queue<Path> q;        cin>>row>>column;        for (i=1;i<=row;i++)            for (j=1;j<=column;j++)                cin>>grid[i][j];        cin>>si>>sj>>ti>>tj;        memset(included,false,sizeof(included));        included[si][sj]=true;        Path add=Path(si,sj,grid[si][sj]);        while(!included[ti][tj]){            for(k=0;k<4;k++){                i=add.i+dirt[k][0];                j=add.j+dirt[k][1];                if(i>=1 && i<=row && j>=1 && j<=column && !included[i][j])                    q.push( Path(i,j,add.dist+grid[i][j]));            }            add=q.top();            while (included[add.i][add.j]){                q.pop();                add = q.top();            }            included[add.i][add.j]=true;        }        cout<<add.dist<<endl;    }    return 0;}