uva 11098 - Battle II（强联通）

题目链接：uva 11098 - Battle II

先将图缩点，每个强连通分量中最小的点权做为新点的点权。所有入度为0的点是一定要的，然后从点权小的开始考虑，如果加入后平均值变小，则加入。最后按照dfs序排序后输出。

#include <cstdio>#include <cstring>#include <vector>#include <stack>#include <queue>#include <algorithm>using namespace std;typedef long long ll;const int maxn = 305;const ll inf = 0x3f3f3f3f3f3f3f3f;int N, X[maxn], Y[maxn], R[maxn], E[maxn];int cntlock, cntscc, sccno[maxn], pre[maxn];vector<int> G[maxn], T[maxn];stack<int> S;struct State {int pre, idx;ll val;State(int pre = 0, int idx = 0, ll val = 0): pre(pre), idx(idx), val(val) {}};inline bool cmpVal(const State& a, const State& b) { return a.val < b.val; }inline bool cmpIdx(const State& a, const State& b) { return a.pre < b.pre; }int dfs (int u) {int lowu = pre[u] = ++cntlock;S.push(u);for (int i = 0; i < G[u].size(); i++) {int v = G[u][i];if (!pre[v]) {int lowv = dfs(v);lowu = min(lowu, lowv);} else if (!sccno[v])lowu = min(lowu, pre[v]);}if (lowu == pre[u]) {cntscc++;while (true) {int x = S.top(); S.pop();sccno[x] = cntscc;if (x == u) break;}}return lowu;}void findSCC() {cntlock = cntscc = 0;memset(pre, 0, sizeof(pre));memset(sccno, 0, sizeof(sccno));for (int i = 0; i < N; i++)if (!pre[i]) dfs(i);}inline ll distance(ll a, ll b) { return a * a + b * b; }bool judge (int a, int b) {ll c = distance((ll)X[a]-X[b], (ll)Y[a]-Y[b]);ll d = (R[a] + R[b] + E[a]); d = d * d;return d >= c;}void init () {scanf("%d", &N);for (int i = 0; i < N; i++)scanf("%d%d%d%d", &X[i], &Y[i], &R[i], &E[i]);for (int i = 0; i < N; i++) {G[i].clear();for (int j = 0; j < N; j++) if (i != j)if (judge(i, j)) G[i].push_back(j);}findSCC();}void solve () {ll C[maxn], sum = 0;int in[maxn], rec[maxn];memset(in, 0, sizeof(in));for (int i = 1; i <= cntscc; i++)C[i] = inf, T[i].clear();for (int i = 0; i < N; i++) {int u = sccno[i];if (C[u] > E[i]) {C[u] = E[i];rec[u] = i;}for (int j = 0; j < G[i].size(); j++) {int v = sccno[G[i][j]];if (u != v) {T[v].push_back(u);in[u]++;}}}int p = 0, c = 0;queue<int> que;vector<State> ans, tmp;for (int i = 1; i <= cntscc; i++) if (!in[i]) que.push(i);while (!que.empty()) {int u = que.front();que.pop();pre[u] = cntlock++;if (T[u].size() == 0) {ans.push_back(State(p++, rec[u], C[u]));sum += C[u], c++;} elsetmp.push_back(State(p++, rec[u], C[u]));for (int i = 0; i < T[u].size(); i++) {int v = T[u][i];in[v]--;if (in[v] == 0) que.push(v);}}sort(tmp.begin(), tmp.end(), cmpVal);p = 0;while (p < tmp.size()) {if (tmp[p].val * c >= sum) break;ans.push_back(tmp[p]);sum += tmp[p].val;c++, p++;}sort(ans.begin(), ans.end(), cmpIdx);for (int i = 0; i < ans.size(); i++)printf(" %d", ans[i].idx);printf("\n");}int main () {int cas;scanf("%d", &cas);for (int kcas = 1; kcas <= cas; kcas++) {init();printf("Case #%d:", kcas);solve();}return 0;}