hiho一下 第六十六周

题目链接:这是一道水爆了的广搜题

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
using namespace std;
const int maxn = 2 * 1e5 + 7;
typedef long long ll;
#define re(i,n) for(int i=0;i<n;i++) 
char a[107][107];
int b[107][107];
int n, m;
int sx, sy;
struct Point{
    int x, y;
};
struct Q{
    Point a[10000];
    int h, r;
    void init(){ h = r = 0; }
    void enq(int x, int y){
        a[r].x = x, a[r].y = y, r++;
    }
    Point deq(){ 
        return a[h++];
    }
}q;
int dir[4][2] = {0,1,1,0,0,-1,-1,0};
void go(){
    memset(b, -1, sizeof(b));
    b[sx][sy] = 0;
    q.init();
    q.enq(sx, sy);
    while (q.h != q.r){
        Point me = q.deq();
        re(i, 4){
            int x = me.x + dir[i][0], y = me.y + dir[i][1];
            if (b[x][y] != -1)continue;
            if (a[x][y] == '.'){ 
                b[x][y] = b[me.x][me.y] + 1;
                q.enq(x, y); 
            }
            else if (a[x][y] == 'S'){
                b[x][y] =  b[me.x][me.y] + 1;
            }
        }
    }
}
int main(){
    freopen("in.txt", "r", stdin);
    cin >> n >> m;
    re(i, n)re(j, m){
        cin >> a[i + 1][j + 1]; 
        if (a[i + 1][j + 1] == 'P')a[i + 1][j + 1] = '#';
        else if (a[i + 1][j + 1] == 'H'){
            sx = i + 1, sy = j + 1;
            a[sx][sy] = '.';
        }
    }
    re(i, n + 1)a[i][m + 1] = a[i][0] = '#';
    re(i, m + 1)a[0][i] = a[n + 1][i] = '#';
    go();/*
    re(i, n + 1){
        re(j, m + 1){
            printf("%3d", b[i][j]);
        }
        puts("");
    }*/
    int ans = 1e5;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            if (a[i][j] == 'S'){
                if (b[i][j] == -1)continue;
                re(k, 4){
                    int x = i + dir[k][0], y = j + dir[k][1];
                    if (a[x][y] == 'S'){
                        if (b[x][y] != -1){
                            int now = b[x][y] + b[i][j];
                            ans = min(now, ans);
                        }
                    }
                }
            }
        }
    }
    if (ans == 1e5){
        puts("Hi and Ho will not have lunch.");
    }
    else{
        printf("%d
", ans);
    }
    return 0;
}