基础练习 回形取数

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<stdlib.h>
 4 #include<string.h>
 5 #include<algorithm>
 6 using namespace std;
 7 int a[250][250];
 8 
 9 int main(){
10     int n, m;
11    // memset(vis, 0, sizeof(vis));
12     memset(a, -1, sizeof(a));
13     cin >> n >> m;
14     for(int i = 0; i < n; i++){
15         for(int j = 0; j < m; j++){
16             scanf("%d", &a[i][j]);
17         }
18     }
19     int x = -1, y = 0, cnt = 0;
20     while(cnt < n * m){
21         while(x + 1 < n && a[x + 1][y] != -1){
22             printf("%d ", a[++x][y]);
23             a[x][y] = -1;
24             cnt++;
25         }
26         while(y + 1 < m && a[x][y + 1] != -1){
27             printf("%d ", a[x][++y]);
28             a[x][y] = -1;
29             cnt++;
30         }
31         while(x  - 1 >= 0 && a[x - 1][y] != -1){
32             printf("%d ", a[--x][y]);
33             a[x][y] = -1;
34             cnt++;
35         }
36         while(y - 1 >= 0 && a[x][y - 1] != -1){
37             printf("%d ", a[x][--y]);
38             a[x][y] = -1;
39             cnt++;
40         }
41     }
42     cout << endl;
43     return 0;
44 }