ABC358C Popcorn

atcoder/abc358c_popcorn.cpp

@@ -0,0 +1,53 @@
+// Vicfred
+// https://atcoder.jp/contests/abc358/tasks/abc358_c
+// brute force, bitmask
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int countbits(int n) {
+  int count = 0;
+  while (n) {
+    count += n & 1;
+    n >>= 1;
+  }
+  return count;
+}
+
+int main() {
+  int N, M;
+  cin >> N >> M;
+  vector<int> X(N);
+  for (int i = 0; i < N; ++i) {
+    string S;
+    cin >> S;
+    for (int j = 0; j < M; ++j) {
+      if (S[j] == 'o') {
+        X[i] = X[i] | (1 << j);
+      }
+    }
+  }
+  // for(int i = 0; i < N; ++i) {
+  //   cout << X[i] << endl;
+  // }
+  int minima = 1 << 30;
+  for (int mask = 0; mask < (1 << N); ++mask) {
+    // cout << "mask: " << mask << endl;
+    int stalls = 0;
+    for (int bit = 0; bit < N; ++bit) {
+      if (mask & (1 << bit)) {
+        // cout << "bit " << bit << " prendido" << endl;
+        stalls = stalls | X[bit];
+        // cout << "adding: " << X[bit] << endl;
+        // cout << "stalls: " << stalls << endl;
+      }
+    }
+    bool valid = stalls == (1 << M) - 1;
+    if (valid) {
+      minima = min(minima, countbits(mask));
+    }
+  }
+  cout << minima << endl;
+  return 0;
+}