Merge pull request #71 from InflixOP/patch1

Create #2845. Count of Interesting Subarrays.cpp

Author: InflixOP

#2845. Count of Interesting Subarrays.cpp

@@ -0,0 +1,21 @@
+class Solution {
+public:
+    long long countInterestingSubarrays(vector<int>& nums, int mod, int k) {
+        int n=nums.size();
+        vector<int>pref(n,0);
+        map<int,int>mp;
+        int cnt=0;
+        long long ans=0;
+        mp[0]=1;
+        for(int i=0;i<n;i++){
+            pref[i]=(nums[i]%mod==k)+cnt;
+            int l=pref[i]%mod;
+            if(mp.find((l-k+mod)%mod)!=mp.end()){
+                ans+=mp[(l-k+mod)%mod];
+            }
+            cnt=pref[i];
+            mp[l]++;
+        }
+        return ans;
+    }
+};