08-06-2024

Author: Hasheditz

LeetCode/523. Continuous Subarray Sum.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    bool checkSubarraySum(vector<int>& nums, int k) {
+        int n = nums.size();
+        vector<int>prefixMod(n+1,0);
+        int sum = 0;
+        for(int i = 0; i < n; i++){
+            sum += nums[i];
+            prefixMod[i+1] = sum % k;
+        }
+        unordered_map<int,int>mp;
+        for(int i = 0; i < n+1; i++){
+            auto it = mp.find(prefixMod[i]);
+            if(it != mp.end()){
+                if(i - it->second >= 2) return true;
+            }else{
+                mp[prefixMod[i]] = i;
+            }
+        }
+        return false;
+    }
+};