题解

#include<bits/stdc++.h>
using namespace std;
int n, m, a[100005];
int func(int x) {
    int cnt = 0;
    for (int i = 1; i <= n; i++) {
        int j = i, sum = 0;
        cnt++;
        while (j <= n && sum + a[j] <= x)
            sum += a[j++];
        i = j - 1;
    }
    return cnt;
}
int main(){
	cin >> n >> m;
    int sum = 0, maxn = 0;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum += a[i];
        maxn = max(a[i], maxn);
    }
    int l = maxn, r = sum, ans;
    while (l <= r) {
        int mid = (l + r) / 2;
        if(func(mid) <= m){
            ans = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    cout << ans;
	return 0;
}