题目： 98. 所有可达路径
代码：
#include <iostream>
#include <vector>
using namespace std;
void dfs(vector<vector<bool>>& graph, int start, int end, vector<int>& cur, vector<vector<int>>& result) {
if(start == end) {
result.push_back(cur);
return;
}
for(int i = 1; i <= end; i++) {
if(graph[start][i]) {
cur.push_back(i);
dfs(graph, i, end, cur, result);
cur.pop_back();
}
}
}
int main(void) {
int m, n;
cin >> n >> m;
vector<vector<bool>> graph(n + 1, vector<bool>(n + 1));
while(m--) {
int x, y;
cin >> x >> y;
graph[x][y] = true;
}
vector<vector<int>> result;
vector<int> path;
path.push_back(1);
dfs(graph, 1, n, path, result);
if(result.size() == 0) {
cout << -1 << endl;
return 0;
}
for(int i = 0; i < result.size(); i++) {
for(int j = 0; j < result[i].size(); j++) {
if(j > 0) {
cout << " ";
}
cout << result[i][j];
}
cout << endl;
}
return 0;
}
