leetcode2845. 统计趣味子数组的数目

题解

class Solution {
public:
    long long countInterestingSubarrays(vector<int>& nums, int modulo, int k) {
        int a[100010];
        unordered_map<int, int> mp;
        mp[0] = 1;
        long long ans = 0;
        int pre = 0;
        for(int x : nums)
        {
            pre += x % modulo == k;
            ans += mp[(pre-k+modulo) % modulo];
            mp[pre%modulo]++;
        }
        return ans;
    }
};