数列分段2

要判断单个元素是否超过阈值。

n,m = map(int,input().split())
a = [0] + list(map(int,input().split()))
r = sum(a)
l = 1
s = [0] * (n + 1)
for i in range(1,n + 1):
    s[i] = a[i] + s[i - 1]
def check(mid):
    i = 1 # 当前元素下标
    last = 0 # 上一段结尾元素的下标
    part = 1 # 目前在第几段
    while i <= n: # 保证数组不越界
        if s[i] - s[last] <= mid:
            i = i + 1
        else:
            if s[i] - s[i - 1] > mid:
                return False
            last = i - 1
            part = part + 1
    if part <= m:
        return True
    else:
        return False

while l < r:
    mid = (l + r) // 2
    if check(mid):
        r = mid
    else:
        l = mid + 1
print(r)