feat: 2845. Count of Interesting Subarrays, hash+前缀和

Author: upupming

leetcode/残酷刷题/2845. Count of Interesting Subarrays.js

@@ -0,0 +1,20 @@
+/**
+ * @param {number[]} nums
+ * @param {number} modulo
+ * @param {number} k
+ * @return {number}
+ */
+var countInterestingSubarrays = function(nums, m, k) {
+  // mp[余数] = 出现的次数
+  let n = nums.length, mp = {}, r = 0, ans = 0
+  mp[0] = 1
+  for (let i = 0; i < n; i++) {
+      // console.log(nums[i] % m === k, (nums[i] % m) === k)
+      r = (r + (nums[i] % m === k)) % m
+      let target = (r-k+m)%m
+      ans += mp[target] ?? 0
+      // console.log(i, nums[i], r, mp[r], ans)
+      mp[r] ??=0, mp[r]++
+  }
+  return ans
+};