First  Recurring Character

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// Google Question // Given an array = [2,5,1,2,3,5,1,2,4]; // It should return 2 // Given an array = [2,1,1,2,3,5,1,2,4]; // It should return 1 // Given an array = [2,3,4,5]; // It should return undefiened const firstRecurringCharacter = (array) => { const map = new Map(); let first; for (let i = 0; i < array.length; i++) { let count = map.get(array[i]) | 1; if (!map.get(array[i])) { map.set(array[i], count); } else { if (!first) { // At this point we know which is the first recurring character, // so it doesn't matter if we add anything in first variable // and we can use it to store the actual character first = array[i]; break; } first = count + 1; map.set(array[i], count + 1); } } return first; }; console.log(firstRecurringCharacter([2, 1, 1, 2, 3, 5, 1, 2, 4])); console.log(firstRecurringCharacter([2, 5, 1, 2, 3, 5, 1, 2, 4])); console.log(firstRecurringCharacter([2, 3, 4, 5]));
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