June25: Good Subset of matrix [H]

Hard, subset

daily/June25.cpp

@@ -0,0 +1,48 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+ public:
+  /**
+   * @brief LC: 2732: Good Subset of Matrix [H]
+   * Time:
+   * Space:
+   *
+   * @param grid
+   * @return vector<int>
+   */
+  vector<int> goodSubsetofBinaryMatrix(vector<vector<int>>& grid) {
+    vector<int> a[1 << 5];
+    vector<int> ans;
+    int m = grid.size();
+    int n = grid[0].size();
+    for (int i = 0; i < m; i++) {
+      int s = 0;
+      for (auto c : grid[i]) {
+        s = (s << 1) + c;
+      }
+      if (s == 0) {
+        ans.push_back(i);
+        return ans;
+      }
+      a[s].push_back(i);
+    }
+    for (int i = 0; i < (1 << n); i++) {
+      if (a[i].size() == 0) {
+        continue;
+      }
+      for (int j = i + 1; j < (1 << n); j++) {
+        if (a[j].size() == 0) {
+          continue;
+        }
+        if ((i & j) == 0) {
+          ans.push_back(a[i][0]);
+          ans.push_back(a[j][0]);
+          sort(ans.begin(), ans.end());
+          return ans;
+        }
+      }
+    }
+    return ans;
+  }
+};