chromatic number test

Author: adamant-pwn

verify/math/chromatic_number.test.cpp

@@ -0,0 +1,65 @@
+// @brief Chromatic Number
+#define PROBLEM "https://judge.yosupo.jp/problem/chromatic_number"
+#pragma GCC optimize("O3,unroll-loops")
+#include <bits/allocator.h>
+#pragma GCC target("avx2")
+#include <iostream>
+#include "blazingio/blazingio.min.hpp"
+#define CP_ALGO_CHECKPOINT
+#include "cp-algo/number_theory/modint.hpp"
+#include "cp-algo/math/subset_convolution.hpp"
+#include "cp-algo/math/poly.hpp"
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int mod = 998244353;
+using base = cp_algo::math::modint<mod>;
+using polyn = cp_algo::math::poly_t<base>;
+
+cp_algo::big_vector<base> indep_subsets(auto const& adj) {
+    uint32_t n = (uint32_t)size(adj);
+    uint32_t masks = 1 << n;
+    cp_algo::big_vector<base> indep(masks);
+    indep[0] = base(1);
+    for(uint32_t v = 0; v < n; v++) {
+        uint32_t delta = 1 << v;
+        if (adj[v] & delta) continue;
+        for(uint32_t mask = 0; mask < delta; mask++) {
+            indep[mask + delta] = (adj[v] & mask) ? base(0) : indep[mask];
+        }
+    }
+    return indep;
+}
+
+void solve() {
+    size_t n, m;
+    cin >> n >> m;
+    vector<uint64_t> adj(n);
+    for(size_t i = 0; i < m; i++) {
+        int u, v;
+        cin >> u >> v;
+        adj[u] |= 1 << v;
+        adj[v] |= 1 << u;
+    }
+    auto indep = indep_subsets(adj);
+    cp_algo::big_vector<base> w(1 << n);
+    w.back() = 1; // w[S] = 1 if S is the full set, else 0
+    auto Y = cp_algo::math::subset_power_projection<base>(indep, w, n+1);
+    size_t ans = 0;
+    while(Y[ans] == base(0)) {
+        ans++;
+    }
+    cout << ans << "\n";
+}
+
+signed main() {
+    //freopen("input.txt", "r", stdin);
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    int t;
+    t = 1;// cin >> t;
+    while(t--) {
+        solve();
+    }
+}