737bdd0a23
Write a function merging two sorted arrays into one sorted array.
63 lines
1.5 KiB
TypeScript
63 lines
1.5 KiB
TypeScript
function mergeArrays(xs: Array<number>, ys: Array<number>): Array<number> {
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let i = 0;
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let j = 0;
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const result = [];
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for (let q = 0; q < xs.length + ys.length; q += 1) {
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if (i === xs.length) {
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while (j < ys.length) {
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result.push(ys[j]);
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j += 1;
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}
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} else if (j === ys.length) {
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while (i < xs.length) {
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result.push(xs[i]);
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i += 1;
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}
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} else if (xs[i] < ys[j]) {
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result.push(xs[i]);
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i += 1;
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} else {
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result.push(ys[j]);
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j += 1;
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}
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}
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return result;
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}
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// Tests
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let desc = "both arrays are empty";
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let actual = mergeArrays([], []);
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let expected = [];
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assertDeepEqual(actual, expected, desc);
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desc = "first array is empty";
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actual = mergeArrays([], [1, 2, 3]);
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expected = [1, 2, 3];
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assertDeepEqual(actual, expected, desc);
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desc = "second array is empty";
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actual = mergeArrays([5, 6, 7], []);
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expected = [5, 6, 7];
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assertDeepEqual(actual, expected, desc);
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desc = "both arrays have some numbers";
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actual = mergeArrays([2, 4, 6], [1, 3, 7]);
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expected = [1, 2, 3, 4, 6, 7];
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assertDeepEqual(actual, expected, desc);
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desc = "arrays are different lengths";
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actual = mergeArrays([2, 4, 6, 8], [1, 7]);
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expected = [1, 2, 4, 6, 7, 8];
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assertDeepEqual(actual, expected, desc);
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function assertDeepEqual(a: Array<number>, b: Array<number>, desc: string) {
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const aStr = JSON.stringify(a);
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const bStr = JSON.stringify(b);
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if (aStr !== bStr) {
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console.log(`${desc} ... FAIL: ${aStr} != ${bStr}`);
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} else {
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console.log(`${desc} ... PASS`);
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}
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}
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