Update 1349-maximum-students-taking-exam.js

Author: everthis

1349-maximum-students-taking-exam.js

@@ -1,3 +1,59 @@
+/**
+ * @param {character[][]} seats
+ * @return {number}
+ */
+const maxStudents = function(seats) {
+  const m = seats.length, n = seats[0].length, limit = 1 << n
+  const dp = Array.from({ length: m + 1}, () => Array(limit).fill(0))
+  
+  let res = 0
+  for(let i = 1; i <= m; i++) {
+    for(let mask = 0; mask < limit; mask++) {
+      let valid = true
+      for(let j = 0; j < n; j++) {
+        if(seats[i - 1][j] === '#' && ((mask >> j) & 1) ) {
+          valid = false
+          break
+        }
+        if(j < n - 1 && ((mask >> j) & 1) && ((mask >> (j + 1)) & 1) ) {
+          valid = false
+          break
+        }
+      }
+      
+      if(!valid) {
+        dp[i][mask] = -1
+        continue
+      }
+      
+      for(let pre = 0; pre < limit; pre++) {
+        if(dp[i - 1][pre] === -1) continue
+        if( (pre & (mask >> 1)) !== 0 || (pre & (mask << 1)) !== 0 ) continue
+        dp[i][mask] = Math.max(dp[i][mask], dp[i - 1][pre])
+      }
+      
+      dp[i][mask] += bitCnt(mask)
+      
+      res = Math.max(res, dp[i][mask])
+    }
+  }
+  
+  return res
+  
+  function bitCnt(num) {
+    let res = 0
+    while(num) {
+      if(num & 1) res++
+      num = num >> 1
+    }
+    
+    return res
+  }
+};
+
+// another
+
+
 /**
  * @param {character[][]} seats
  * @return {number}