arr
의 길이 측정arr
순회function findSpecialInteger(arr: number[]): number {
const len = arr.length
const target = len / 4
let curFrequent = 1
for(let i = 1; i < len; i++) {
if(arr[i] === arr[i - 1]) {
curFrequent++
if(curFrequent > target) return arr[i]
continue
}
curFrequent = 1
}
return arr.at(-1)
};