494. Target Sum

Author: amitbansal7

target-sum.cpp

@@ -0,0 +1,23 @@
+// Runtime: 4 ms
+// Memory Usage: 8.7 MB
+class Solution {
+public:
+  int findTargetSumWays(vector<int>& nums, int S) {
+    int sum = accumulate(nums.begin(), nums.end(), 0);
+
+    if (sum < S || S < -sum || (sum + S) % 2 == 1)
+      return 0;
+
+    int target = (sum + S) >> 1;
+
+    vector<int> dp(target + 1, 0);
+    dp[0] = 1;
+
+    for (int a : nums) {
+      for (int s = target; s >= a; s--) {
+        dp[s] += dp[s - a];
+      }
+    }
+    return dp[target];
+  }
+};