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https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
56 lines
1.6 KiB
C++
56 lines
1.6 KiB
C++
typedef pair<int, int> PII;
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PII tmp[MAXN];
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int dis[MAXN][MAXN]; int map[MAXN][MAXN];
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int vis[MAXN], q[MAXN], inp[MAXN];
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int Dfs(int u) {
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vis[u] = true; int ret = 1;
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for (int i = 1; i <= n; i++) if (map[u][i] && !vis[i]) ret += Dfs(i);
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return ret;
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}
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int Zhuliu(void) {
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memset(map, 0, sizeof map);
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memset(vis, 0, sizeof vis);
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if (Dfs(1) != n) return -1;
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int done = 0;
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while (true) {
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memset(vis, 0, sizeof vis); memset(inp, 0, sizeof inp);
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int Ans = 0;
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for (int i = 1; i <= n; i++) vis[i] = i;
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for (int i = 2; i <= n; i++) {
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tmp[i] = PII(1000000000, 0);
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for (int j = 1; j <= n; j++) if (map[j][i] == 1) tmp[i] = min(tmp[i], PII(dis[j][i], j));
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inp[tmp[i].second]++; if (tmp[i].second) Ans += tmp[i].first;
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}
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int head = 1, tail = 0;
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for (int i = 1; i <= n; i++) if (!inp[i]) q[++tail] = i;
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while (head <= tail) {
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int now = q[head++];
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if (!--inp[tmp[now].second]) q[++tail] = tmp[now].second;
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}
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bool ok = true;
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for (int i = 1, t; i <= n; i++) if (inp[i] > 0) {
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t = i; ok = false;
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do {
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inp[t] = -i;
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t = tmp[t].second;
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vis[t] = i;
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} while (t != i);
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}
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if (ok) return Ans + done;
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for (int i = 1; i <= n; i++) if (inp[i] < 0) {
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done += tmp[i].first;
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for (int j = 1; j <= n; j++) if (vis[j] != vis[i]) {
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if (map[i][j]) {
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map[vis[i]][vis[j]] = 1;
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dis[vis[i]][vis[j]] = min(dis[vis[i]][vis[j]], dis[i][j]);
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}
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if (map[j][i]) {
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dis[vis[j]][vis[i]] = min(dis[vis[j]][vis[i]], dis[j][i] - tmp[i].first);
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map[vis[j]][vis[i]] = 1;
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}
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}
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if (vis[i] != i) for (int j = 1; j <= n; j++) map[i][j] = map[j][i] = 0;
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}
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}
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}
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