[백준] 1300 - K번째 수 (파이썬)

n = int(input())
k = int(input())
a = [2*n-1]

for i in range(n-1,0,-1):
    a.append(a[-1]+2*i-1)

def binary_search(start,end,target):
    if start>end:
        return start
    
    mid = (start+end)//2
    if a[mid] > target:
        return binary_search(start,mid-1,target)
    elif a[mid] == target:
        return mid
    else:
        return binary_search(mid+1,end,target)

print(binary_search(0,len(a),k)+1)

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