题目：98. 所有可达路径 (kamacoder.com)
邻接矩阵表示图
#include<bits/stdc++.h>using namespace std;vector<vector<int>> reslut;
vector<int> path;void dfs(vector<vector<int>>& map, int start, int end) {if(start == end) {reslut.push_back(path);return;}for(int i = 1;i < map.size();i++) {if(map[start][i] == 1) {path.push_back(i);dfs(map, i, end);path.pop_back();}}
}int main() {int n, m;cin >> n >> m;vector<vector<int>> map(n + 1, vector<int>(n + 1, 0));for(int i = 0;i < m;i++) {int x,y;cin >> x >> y;map[x][y] = 1;}path.push_back(1);dfs(map, 1, n);if(reslut.size() == 0) cout << -1 << endl;else {for(int i = 0;i < reslut.size();i++) {for(int j = 0;j < reslut[i].size() - 1;j++) {cout << reslut[i][j] << ' ';}cout << reslut[i][reslut[i].size() - 1] << endl;}}return 0;
}邻接表表示图:
#include <iostream>
#include <vector>
#include <list>using namespace std;vector<vector<int>> result;
vector<int> path;void dfs(vector<list<int>>& map, int x, int n) {if(x == n) {result.push_back(path);return;}for(int i : map[x]) {path.push_back(i);dfs(map, i, n);path.pop_back();}
}int main() {int n, m, x, y;cin >> n >> m;vector<list<int>> graph(n + 1);while(m--) {cin >> x >> y;graph[x].push_back(y);}path.push_back(1);dfs(graph, 1, n);if(result.size() == 0) cout << -1 << endl;else {for(int i = 0;i < result.size();i++) {int size = result[i].size();for(int j = 0;j < size - 1;j++) {cout << result[i][j] << ' ';}cout << result[i][size - 1] << endl;} }return 0;
}