binary search
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const search = function(arr, target){
let l = 0; r= arr.length-1;
while(l<=r){
let m = Math.floor((l+r)/2);
if(target === arr[m]) return m;
else if(target <= arr[m]) r = m-1;
else l = m+1;
}
return -1;
}
console.log(search([5,7,9,19,99],99));
JavaScript
INFO