本题属于最基础的拓扑排序。大意就是,给出一个数n, 然后底下n行,编号1到n, 每行输入几个数,保证结果中该行的编号要在这几个数前面。
/* ID: sdj22251 PROG: calfflac LANG: C++ */ #include <iostream> #include <vector> #include <list> #include <map> #include <set> #include <deque> #include <queue> #include <stack> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <cctype> #include <string> #include <cstring> #include <cmath> #include <ctime> #define MAX 100000000 #define LOCA #define PI acos(-1.0) using namespace std; int n, m; int in[201]; int ans[201]; vector<int>v[201]; void topsort() { int i, ct = 0; queue<int>q; for(i = 1; i <= n; i++) { if(in[i] == 0) q.push(i); } while(!q.empty()) { int first = q.front(); ans[ct++] = first; q.pop(); int size = v[first].size(); for(i = 0; i < size; i++) { int can_reach = v[first][i]; in[can_reach]--; if(in[can_reach] == 0) q.push(can_reach); } } } int main() { #ifdef LOCAL freopen("ride.in","r",stdin); freopen("ride.out","w",stdout); #endif int i, tmp; scanf("%d", &n); for(i = 1; i <= n; i++) { while(1) { scanf("%d", &tmp); if(tmp == 0) break; v[i].push_back(tmp); in[tmp]++; } } topsort(); for(i = 0; i < n - 1; i++) printf("%d ", ans[i]); printf("%d\n", ans[n - 1]); return 0; }