partitiona equal subset

Author: dingjy94

algorithm/DP/knapsack/partitionEqualSubset.js

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+/**
+ * lc416 (https://leetcode.com/problems/partition-equal-subset-sum/)
+ * Given a non-empty array containing only positive integers,
+ * find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal.
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var canPartition = function (nums) {
+  const sum = nums.reduce((acc, num) => acc + num, 0);
+  if (sum % 2 === 1) {
+    return false;
+  }
+
+  const half = sum / 2;
+
+  const dp = [];
+  for (let i = 0; i <= nums.length; i++) {
+    dp[i] = [];
+    dp[i][0] = true;
+  }
+
+  for (let j = 0; j <= half; j++) {
+    dp[0][j] = false;
+  }
+  dp[0][0] = true;
+
+  for (let i = 1; i <= nums.length; i++) {
+    for (let j = 1; j <= half; j++) {
+      dp[i][j] = dp[i - 1][j];
+      if (nums[i - 1] <= j) {
+        dp[i][j] = (dp[i - 1][j - nums[i - 1]] || dp[i][j]);
+      }
+    }
+  }
+
+  return dp[nums.length][half];
+};