题目描述
It’s universally acknowledged that there’re innumerable trees in the campus of HUST.
Now you're going to walk through a large forest. There is a path consisting of N stones winding its way to the other side of the forest. Between every two stones there is a distance. Let di indicates the distance between the stone i and i+1.Initially you stand at the first stone, and your target is the N-th stone. You must stand in a stone all the time, and you can stride over arbitrary number of stones in one step. If you stepped from the stone i to the stone j, you stride a span of (di+di+1+...+dj-1). But there is a limitation. You're so tired that you want to walk through the forest in no more than K steps. And to walk more comfortably, you have to minimize the distance of largest step.
输入描述:
The first line contains two integer N and K as described above.
Then the next line N-1 positive integer followed, indicating the distance between two adjacent stone.
输出描述:
An integer, the minimum distance of the largest step.
示例1
输入
6 3
1 3 2 2 5
输出
It’s universally acknowledged that there’re innumerable trees in the campus of HUST.
Now you're going to walk through a large forest. There is a path consisting of N stones winding its way to the other side of the forest. Between every two stones there is a distance. Let di indicates the distance between the stone i and i+1.Initially you stand at the first stone, and your target is the N-th stone. You must stand in a stone all the time, and you can stride over arbitrary number of stones in one step. If you stepped from the stone i to the stone j, you stride a span of (di+di+1+...+dj-1). But there is a limitation. You're so tired that you want to walk through the forest in no more than K steps. And to walk more comfortably, you have to minimize the distance of largest step.
输入描述:
The first line contains two integer N and K as described above.
Then the next line N-1 positive integer followed, indicating the distance between two adjacent stone.
输出描述:
An integer, the minimum distance of the largest step.
示例1
输入
6 3
1 3 2 2 5
输出
5
#include<bits/stdc++.h> using namespace std; #define ll long long const int MAX = 1e5 + 7; ll a[MAX]; ll s, mx = 0, sum = 0, n, k; void Bsearch() { ll l = mx, r = sum; ll ans; while(l <= r) { ll mid = (l + r) >> 1; s = 0; ll S = 0; for(int i = 1; i <= n - 1; i++) { s += a[i]; if(s > mid) { s = a[i]; S++; } } if(S >= k) l = mid + 1; else { r = mid - 1; ans = mid; } } printf("%lld\n", ans); } int main() { scanf("%lld%lld", &n, &k); for(int i = 1; i <= n - 1; i++) { scanf("%lld", &a[i]); mx = max(mx, a[i]); sum += a[i]; } Bsearch(); return 0; }