这题写起来真的有点麻烦，按照官方题解的写法 先建图，然后求强连通分量，然后判断掉不符合条件的换 最后做dp转移即可 虽然看起来复杂度很高，但是n只有15，所以问题不大
#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ll long long #define ld long double #define null NULL #define all(a) a.begin(), a.end() #define forn(i, n) for (int i = 0; i < n; ++i) #define sz(a) (int)a.size() #define lson l , m , rt << 1 #define rson m + 1 , r , rt << 1 | 1 #define bitCount(a) __builtin_popcount(a) template int gmax(T &a, T b) { if (b > a) { a = b; return 1; } return 0; } template int gmin(T &a, T b) { if (b < a) { a = b; return 1; } return 0; } using namespace std; string to_string(string s) { return '"' + s + '"'; } string to_string(const char* s) { return to_string((string) s); } string to_string(bool b) { return (b ? "true" : "false"); } template string to_string(pair p) { return "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; } template string to_string(A v) { bool first = true; string res = "{"; for (const auto &x : v) { if (!first) { res += ", "; } first = false; res += to_string(x); } res += "}"; return res; } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...); } #ifdef LOCAL #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__) #else #define debug(...) 42 #endif const int MAXN = 75005; vector graph[MAXN]; vector group[MAXN]; int dfn[MAXN], low[MAXN]; int dcnt; int col[MAXN + 5], ccnt; bool vis[MAXN + 5]; int stk[MAXN + 5], tp; vector> dp[32768]; void Tarjan_scc(int u) { dfn[u] = ++dcnt, low[u] = dcnt, vis[u] = true; stk[++tp] = u; for(int i = 0; i < (int)graph[u].size(); i++) { int v = graph[u][i]; if(!dfn[v]) { Tarjan_scc(v); low[u] = min(low[u], low[v]); } else if(vis[v]) low[u] = min(low[u], low[v]); } if(dfn[u] == low[u]) { ++ccnt; while(true) { col[stk[tp]] = ccnt; vis[stk[tp]] = false; if(stk[tp--] == u) break; } } } int main() { int k; while(~scanf("%d", &k)) { tp = -1; ccnt = 0; dcnt = 0; for(int i = 0; i < MAXN; ++i) { dfn[i] = 0; graph[i].clear(); group[i].clear(); } vector sum; vector > vc; map > mp; int tot = 0; ll allSum = 0; for(int i = 0; i < k; ++i) { int x; scanf("%d", &x); ll tmpSum = 0; for(int j = 0; j < x; ++j) { int y; scanf("%d", &y); vc.push_back(make_pair(y, i)); mp[y] = make_pair(tot, i); tot ++; tmpSum += y; } sum.push_back(tmpSum); allSum += tmpSum; } // debug(allSum); if(allSum % k) { printf("No\n"); continue; } allSum /= k; set selfCircle; set> hasEdge; // debug(allSum); for(int i = 0, len = vc.size(); i < len; ++i) { ll searchNum = allSum - sum[vc[i].second] + vc[i].first; if(mp.find(searchNum) == mp.end()) continue; else if( mp[searchNum].second == vc[i].second && mp[searchNum].first != i) { // solve specfial condition continue; } else if(mp[searchNum].first == i) { // debug(i); selfCircle.insert(i); } graph[i].push_back(mp[searchNum].first); hasEdge.insert(make_pair(i, mp[searchNum].first)); debug(i, mp[searchNum].first); } for(int i = 0; i < tot; ++i) { if(!dfn[i]) Tarjan_scc(i); } for(int i = 0; i < tot; ++i) { // printf("%d ", col[i]); group[col[i]].push_back(i); } // printf("\n"); for(int i = 1; i <= ccnt; ++i) { // debug(i, group[i].size()); if(group[i].size() == 1 && selfCircle.count(group[i][0])) { int id = group[i][0]; vector > tmpPair; tmpPair.push_back(make_pair(vc[id].first, vc[id].second + 1)); dp[1< 1) { vector > tmpPair; int tmp = 0; int len = group[i].size(); bool suc = true; for(int j = 0; j < len; ++j) { int to = group[i][j]; if(tmp & (1< 0 && dp[t].size() > 0) { dp[i] = dp[s]; dp[i].insert(dp[i].end(), dp[t].begin(), dp[t].end()); break; } } } auto cmp = [&](pair &A, pair &B) { return mp[A.first].second < mp[B.first].second; }; int end = (1< 0 ) { printf("Yes\n"); // debug(dp[end]); sort(dp[end].begin(), dp[end].end(), cmp); for(int i = 0; i < k; ++i) { printf("%d %d\n", dp[end][i].first, dp[end][i].second); } } else printf("No\n"); } return 0; }
