50178. Longest Cycle
難度：4/5
Second Try: 4/5 Used Time: 20:29 Used Time: 13:121
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49#include <stdio.h>
int n;
int g[8][8];
void swap(int *a, int *b){
int t = *a;
*a = *b;
*b = t;
}
int dfs(int arr[], int now_idx, int arr_len, int target_size){
if(now_idx == target_size){
for(int i = 0; i < now_idx; i++) printf("%d ", arr[i]);
printf("\n");
return 1;
}
else{
for(int i = now_idx; i < arr_len; i++){
if(now_idx == 0 && g[0][arr[i]] == 0) continue;
if(now_idx != 0 && g[arr[now_idx - 1]][arr[i]] == 0) continue;
if(now_idx == target_size - 1 && g[0][arr[i]] == 0) continue;
swap(&arr[now_idx], &arr[i]);
int rtv = dfs(arr, now_idx + 1, arr_len, target_size);
if(rtv) return 1;
swap(&arr[now_idx], &arr[i]);
}
return 0;
}
}
int main(){
scanf("%d", &n);
for(int i = 0; i < n; i++){
for(int j = 0; j < n; j++)
scanf("%d", &g[i][j]);
}
int arr[10] = {0};
for(int i = 0; i < n - 1; i++){
arr[i] = i + 1;
}
for(int i = n - 1; i >= 0; i--){
int rtv = dfs(arr, 0, n - 1, i);
if(rtv) break;
}
}