【日常水题-bfs】马的遍历

这几天日常一搜索qaq

 P1443 马的遍历

#include<cstdio>
#include<iostream>
using namespace std;
const int sz = 410;
int n, m, sx, sy;
int plat[sz][sz], q[sz*100][3];
bool book[sz][sz];
int dx[8] = {-2,-1,1,2,2,1,-1,-2},
    dy[8] = {1,2,2,1,-1,-2,-2,-1};
void bfs(int x, int y) {
    int head = 1, tail = 1, mx, my;
    plat[x][y] = 0;
    book[x][y] = 1;
    q[1][1] = x, q[1][2] = y;
    while(head <= tail) {
        int step = plat[q[head][1]][q[head][2]]+1;
        for(int i = 0; i < 8; i++) {
            mx = q[head][1] + dx[i];
            my = q[head][2] + dy[i];
            if(mx>=1&&my>=1&&mx<=n&&my<=m&&(!book[mx][my])) {
                tail++;
                plat[mx][my] = step;
                book[mx][my] = 1;
                q[tail][1] = mx;
                q[tail][2] = my;
            }
        }
        head++;
    }
    
}
int print() {
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(plat[i][j] == 0 ) {
                if(i==sx&&j==sy) plat[i][j] = 0;
                else plat[i][j] = -1;
            }
            printf("%-5d", plat[i][j]);
        }
        cout<<endl;
    }
}
int main() {
    scanf("%d%d%d%d",&n,&m,&sx,&sy);
    bfs(sx, sy);
    print();
    return 0;
}

十分朴素详实的bfs

感觉bfs全长一个样子QAQ