2996. Smallest Missing Integer Greater Than Sequential Prefix Sum

Author: sergeyleschev

Diff for: 2501-3000/2996. Smallest Missing Integer Greater Than Sequential Prefix Sum.swift

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+class Solution {
+
+    // Solution by Sergey Leschev
+    // 2996. Smallest Missing Integer Greater Than Sequential Prefix Sum
+
+    // Time complexity: O(N * log(N))
+    // Space complexity: O(1)
+
+    func missingInteger(_ nums: [Int]) -> Int {
+        var countSum = nums[0]
+        var sortedNums = Array(nums)
+        sortedNums.sort()
+
+        for i in 1..<nums.count {
+            if nums[i - 1] + 1 == nums[i] {
+                countSum += nums[i]
+            } else {
+                break
+            }
+        }
+
+        for i in 0..<sortedNums.count {
+            if countSum == sortedNums[i] {
+                countSum += 1
+            }
+        }
+        return countSum
+    }
+}