18 lines
603 B
TypeScript
18 lines
603 B
TypeScript
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// Finds the first index which is a duplicate value
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// Returns -1 if there are no duplicates
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// Returns the index of the first duplicate entry it finds
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// Note: This "can" fail if the object entries don't have their properties in the
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// same order.
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export const findDuplicateIndex = (arr: Array<unknown>) => {
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const _uniqSet = new Set();
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let currSetSize = 0;
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for (let i = 0; i < arr.length; i++) {
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// JSON.stringify because value can be objects
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_uniqSet.add(JSON.stringify(arr[i]));
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if (_uniqSet.size > currSetSize) currSetSize = _uniqSet.size;
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else return i;
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}
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return -1;
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};
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