#include using namespace std; int n, r; //此答案,不吸氧,第8个测试点TLE,吸氧后通过。 void dfs(int step, vector path, int m) { if (step == n + 1) return; if (m == r) { for (int i = 0; i < r; i++) printf("%3d", path[i]); printf("\n"); return; } //下一个数字选择上 vector p1 = path; p1.push_back(step + 1); dfs(step + 1, p1, m + 1); //下一个数字放弃掉 dfs(step + 1, path, m); } int main() { cin >> n >> r; dfs(0, {}, 0); return 0; }