add: 和可被K整除的子数组

src/array/subarray-sums-divisible-by-k.js

@@ -0,0 +1,17 @@
+/**
+ * @param {number[]} A
+ * @param {number} K
+ * @return {number}
+ */
+export const subarraysDivByK = function (A, K) {
+  const map = new Map([[0, 1]]); let sum = 0; let count = 0
+
+  A.forEach(n => {
+    sum = (sum + n) % K; sum = sum < 0 ? sum + K : sum
+    const temp = map.get(sum) || 0
+    count += temp
+    map.set(sum, temp + 1)
+  })
+
+  return count
+}