Update bitpack + inv matrix mod 2 test

Author: adamant-pwn

cp-algo/data_structures/bitpack.hpp

@@ -45,6 +45,9 @@ namespace cp_algo::data_structures {
         int operator[](size_t i) const {
             return (data[i / bits_per_block] >> (i % bits_per_block)) & 1;
         }
+        void set(size_t i) {
+            data[i / bits_per_block] |= 1ULL << (i % bits_per_block);
+        }
 
         std::string to_string() const {
             std::string res(blocks * bits_per_block, '0');

verify/data_structures/bitpack/inv_mod_2.test.cpp

@@ -0,0 +1,55 @@
+// @brief Inverse Matrix (Mod 2)
+#define PROBLEM "https://judge.yosupo.jp/problem/inverse_matrix_mod_2"
+#pragma GCC optimize("Ofast,unroll-loops")
+#include "cp-algo/data_structures/bitpack.hpp"
+#include <bits/stdc++.h>
+
+using namespace std;
+using namespace cp_algo::data_structures;
+
+const int maxn = 1 << 13;
+bitpack<maxn> a[maxn];
+
+void solve() {
+    int n;
+    cin >> n;
+    string row;
+    vector<int> lead(n);
+    for(int i = 0; i < n; i++) {
+        cin >> row;
+        a[i] = row;
+        a[i].set(n + i);
+        for(int j = 0; j < i; j++) {
+            if(a[i][lead[j]]) {
+                a[i].xor_hint(a[j], lead[j]);
+            }
+        }
+        lead[i] = a[i].ctz();
+        if(lead[i] >= n) {
+            cout << -1 << "\n";
+            return;
+        }
+        for(int j = 0; j < i; j++) {
+            if(a[j][lead[i]]) {
+                a[j].xor_hint(a[i], lead[i]);
+            }
+        }
+    }
+    for(int i = 0; i < n; i++) {
+        while(lead[i] != i) {
+            swap(a[i], a[lead[i]]);
+            swap(lead[i], lead[lead[i]]);
+        }
+        cout << a[i].to_string().substr(n, n) << "\n";
+    }
+}
+
+signed main() {
+    //freopen("input.txt", "r", stdin);
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    int t = 1;
+    while(t--) {
+        solve();
+    }
+}