lower
, high
로 최소 최대 범위 산정lower
가 high
보다 낮다면 반복function guessNumber(n: number): number {
let lower = 1, high = n
while(lower <= high) {
const mid = Math.floor((lower + high) / 2)
const curr = guess(mid)
if(curr === 0) return mid
if(curr > 0) lower = mid + 1
else if(curr < 0) high = mid - 1
}
return 0
};