sumZero
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// find first pair where the sum is 0 in a sorted array of integer
// Return an array that includes both values that sum to 0
// or undefined if a pair does not exist
//sumZero([-3, -2, -1, 0, 1, 2, 3]) // [-3, 3]
//sumZero([-2, 0, 1, 3]) // undefined
function sumZero(arrInt) {
let leftIndex = 0;
let rightIndex = arrInt.length - 1;
while(leftIndex < rightIndex) {
let sum = arrInt[leftIndex] + arrInt[rightIndex];
if (sum === 0) {
return [arrInt[leftIndex], arrInt[rightIndex]];
} else if(sum > 0) {
rightIndex--;
} else {
leftIndex++;
}
}
return undefined;
}
console.log(sumZero([-3, -2, -1, 0, 1, 2, 3]));
console.log(sumZero([-2, 0, 1, 3]));
JavaScript
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