小C的周末
小C的周末
https://ac.nowcoder.com/acm/problem/15976
并查集+map
#pragma GCC target("avx,sse2,sse3,sse4,popcnt") #pragma GCC optimize("O2,O3,Ofast,inline,unroll-all-loops,-ffast-math") #include <bits/stdc++.h> using namespace std; #define js ios::sync_with_stdio(false);cin.tie(0); cout.tie(0) #define all(vv) (vv).begin(), (vv).end() #define endl "\n" typedef long long ll; typedef unsigned long long ull; typedef long double ld; const ll MOD = 1e9 + 7; inline ll read() { ll s = 0, w = 1; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) if (ch == '-') w = -1; for (; isdigit(ch); ch = getchar()) s = (s << 1) + (s << 3) + (ch ^ 48); return s * w; } inline void write(ll x) { if (!x) { putchar('0'); return; } char F[40]; ll tmp = x > 0 ? x : -x; if (x < 0)putchar('-'); int cnt = 0; while (tmp > 0) { F[cnt++] = tmp % 10 + '0'; tmp /= 10; } while (cnt > 0)putchar(F[--cnt]); } inline ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; } ll qpow(ll a, ll b) { ll ans = 1; while (b) { if (b & 1) ans *= a; b >>= 1; a *= a; } return ans; } ll qpow(ll a, ll b, ll mod) { ll ans = 1; while (b) { if (b & 1)(ans *= a) %= mod; b >>= 1; (a *= a) %= mod; }return ans % mod; } inline int lowbit(int x) { return x & (-x); } const int N = 1e5 + 7; int fa[N], cnt[N], ans[N]; map<int, int> mp[N]; int find(int x) { return x == fa[x] ? x : fa[x] = find(fa[x]); } int main() { js; int n, m, q; while (cin >> n >> m >> q) { for (int i = 1; i <= n; ++i) mp[i].clear(), fa[i] = i; fill(cnt + 1, cnt + m + 1, 0); fill(ans + 1, ans + 1 + m, -1); //初始化-1 for (int i = 1; i <= n; ++i) { int x; cin >> x; ++cnt[x]; ++mp[i][x]; } for (int i = 1; i <= q; ++i) { int u, v; cin >> u >> v; u = find(u), v = find(v); if (mp[u].size() < mp[v].size()) swap(u, v); fa[v] = u; //小的合并到大的里面去 for (auto it : mp[v]) { mp[u][it.first] += it.second; if (mp[u][it.first] == cnt[it.first] and ans[it.first] == -1) //都已连线并且当前ans是没有求解的状态 ans[it.first] = i; } mp[v].clear(); } for (int i = 1; i <= m; ++i) if (cnt[i] == 1) cout << 0 << endl; else if (cnt[i] == -1) cout << -1 << endl; else cout << ans[i] << endl; } return 0; }
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给雨巨打call