/*
Name: NYOJ--284--坦克大战
Author: shen_渊
Date: 14/04/17 19:08
Description: 广度优先搜索+优先队列
注意清空地图
对输入地图进行了预处理,将S,R设置为#
*/
#include<iostream>
#include<queue>
#include<cstring>
using namespace std;
const char YOU = 'Y';
const char TARGET = 'T';
const char RIVER = 'R' ;
const char SWALL = 'S';
const char BWALL = 'B';
const char EMPOTY = 'E';
const char FORBID = '#';
struct node{
int x,y,steps;
node():steps(0){};
bool operator <(const node &a)const{
return steps>a.steps;
}
}you,target;
int bfs();
int check(char);
char map[305][305] = {0};
int m,n;
int dir[4][2] = {{0,1},{0,-1},{1,0},{-1,0}};
int main()
{
// ios::sync_with_stdio(false);
// freopen("in.txt","r",stdin);
while(cin>>m>>n, m || n) {
int i,j;
memset(map,0,sizeof(map));
for(i=1; i<=m; ++i){
for(j=1; j<=n; ++j){
cin>>map[i][j];
switch(map[i][j]){
case YOU:{
you.x = i;you.y = j;
break;
}
case TARGET:{
target.x = i;target.y = j;
break;
}
case RIVER:
case SWALL:{
map[i][j] =='#';
break;
}
default:break;
}
}
}
cout<<bfs()<<endl;
}
return 0;
}
int bfs(){
priority_queue<node> Q;
while(!Q.empty())Q.pop();
Q.push(you);
map[you.x][you.y] = '#';
while(!Q.empty()){
node p = Q.top();Q.pop();
int i,j;
for(i=0; i<4; ++i){
node a;
a.x = p.x + dir[i][0];
a.y = p.y + dir[i][1];
if(a.x<1|| a.y<1|| a.x>m|| a.y>n)continue;
int next;
if(next = check(map[a.x][a.y])){
a.steps = p.steps + next;
if(a.x == target.x && a.y == target.y)return a.steps;
Q.push(a);
map[a.x][a.y] = '#';
}
}
}
return -1;
}
int check(char ch){
switch(ch){
case TARGET:return 1;
case EMPOTY:return 1;
case BWALL:return 2;
}
return 0;
}
NYOJ--284--广搜+优先队列--坦克大战
最新推荐文章于 2022-08-20 14:18:05 发布