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October 10, 2017 07:25
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Get number w/o pair in the array of numbers (two unique numbers)
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function getUniqueNumbersInArray(arr) { | |
let first = 0, second = 0; | |
// xor by each element | |
let xor = arr[0]; | |
for (let i = 1; i < arr.length; i++) { | |
xor ^= arr[i]; | |
} | |
// берем крайний правый ненулевой бит | |
// в нашем примере, xor = 14 (1110); 13 (1101) | |
let rightBit = xor & ~(xor-1); // 2 (0010) | |
// Находим xor для всех элементов у которых этот бит установлен в 1 | |
for (let i = 0; i < arr.length; i++) { | |
if ((arr[i] & rightBit) > 0) { | |
first ^= arr[i]; | |
} | |
} | |
// second = first ^ (first^second) | |
second = first ^ xor; | |
console.info(first); | |
console.info(second); | |
} | |
const arr = [ 0, 4, -1, 7, -1, 4, 9, 0]; | |
getUniqueNumbersInArray(arr); |
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