303. Range Sum Query - Immutable (#59)

Author: Kohei Asai

solutions/rangeSumQueryImmutable.test.ts

@@ -0,0 +1,75 @@
+import NumArray from "./rangeSumQueryImmutable";
+
+describe("303. Range Sum Query - Immutable", () => {
+  test("#1", () => {
+    const numArray = new NumArray([-2, 0, 3, -5, 2, -1]);
+
+    expect(numArray.sumRange(0, 2)).toBe(1);
+    expect(numArray.sumRange(2, 5)).toBe(-1);
+    expect(numArray.sumRange(0, 5)).toBe(-3);
+  });
+
+  test("#2", () => {
+    const numArray = new NumArray([
+      -8261,
+      2300,
+      -1429,
+      6274,
+      9650,
+      -3267,
+      1414,
+      -8102,
+      6251,
+      -5979,
+      -5291,
+      -4616,
+      -4703
+    ]);
+
+    expect(numArray.sumRange(0, 8)).toBe(4830);
+    expect(numArray.sumRange(4, 5)).toBe(6383);
+    expect(numArray.sumRange(9, 11)).toBe(-15886);
+    expect(numArray.sumRange(2, 11)).toBe(-5095);
+    expect(numArray.sumRange(0, 12)).toBe(-15759);
+    expect(numArray.sumRange(9, 12)).toBe(-20589);
+    expect(numArray.sumRange(2, 5)).toBe(11228);
+    expect(numArray.sumRange(0, 9)).toBe(-1149);
+    expect(numArray.sumRange(5, 9)).toBe(-9683);
+    expect(numArray.sumRange(0, 1)).toBe(-5961);
+    expect(numArray.sumRange(12, 12)).toBe(-4703);
+    expect(numArray.sumRange(6, 7)).toBe(-6688);
+    expect(numArray.sumRange(5, 8)).toBe(-3704);
+    expect(numArray.sumRange(1, 1)).toBe(2300);
+    expect(numArray.sumRange(6, 7)).toBe(-6688);
+    expect(numArray.sumRange(10, 11)).toBe(-9907);
+    expect(numArray.sumRange(11, 12)).toBe(-9319);
+    expect(numArray.sumRange(7, 8)).toBe(-1851);
+    expect(numArray.sumRange(4, 11)).toBe(-9940);
+    expect(numArray.sumRange(8, 9)).toBe(272);
+    expect(numArray.sumRange(4, 11)).toBe(-9940);
+    expect(numArray.sumRange(2, 9)).toBe(4812);
+    expect(numArray.sumRange(2, 6)).toBe(12642);
+    expect(numArray.sumRange(11, 12)).toBe(-9319);
+    expect(numArray.sumRange(5, 8)).toBe(-3704);
+    expect(numArray.sumRange(11, 11)).toBe(-4616);
+    expect(numArray.sumRange(1, 9)).toBe(7112);
+    expect(numArray.sumRange(12, 12)).toBe(-4703);
+    expect(numArray.sumRange(10, 10)).toBe(-5291);
+    expect(numArray.sumRange(4, 7)).toBe(-305);
+    expect(numArray.sumRange(12, 12)).toBe(-4703);
+    expect(numArray.sumRange(8, 10)).toBe(-5019);
+    expect(numArray.sumRange(7, 9)).toBe(-7830);
+    expect(numArray.sumRange(4, 7)).toBe(-305);
+    expect(numArray.sumRange(0, 7)).toBe(-1421);
+    expect(numArray.sumRange(8, 9)).toBe(272);
+    expect(numArray.sumRange(10, 12)).toBe(-14610);
+    expect(numArray.sumRange(0, 9)).toBe(-1149);
+    expect(numArray.sumRange(10, 12)).toBe(-14610);
+    expect(numArray.sumRange(7, 12)).toBe(-22440);
+    expect(numArray.sumRange(9, 9)).toBe(-5979);
+    expect(numArray.sumRange(0, 12)).toBe(-15759);
+    expect(numArray.sumRange(1, 3)).toBe(7145);
+    expect(numArray.sumRange(8, 8)).toBe(6251);
+    expect(numArray.sumRange(7, 10)).toBe(-13121);
+  });
+});

solutions/rangeSumQueryImmutable.ts

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+// 303. Range Sum Query - Immutable
+// https://leetcode.com/problems/range-sum-query-immutable/
+class NumArray {
+  constructor(nums: number[]) {
+    let total = 0;
+
+    // [1, 2, 3, 4] -> [1, 3, 6, 10]
+    for (let i = 0; i < nums.length; ++i) {
+      total += nums[i];
+
+      this.sums.push(total);
+    }
+  }
+
+  private sums: number[] = [];
+
+  // sumRange(2, 5) == sumRange(0, 5) - sumRange(0, 1)
+  sumRange(i: number, j: number): number {
+    return this.sums[j] - (this.sums[i - 1] || 0);
+  }
+}
+
+export default NumArray;