Bpartition

#include<stdio.h>

int main()
{
    int n,k;
    scanf("%d %d",&n,&k);
    int arr[n];
    int maxsum = 0;
    for(int i = 0 ; i < n ; i ++){
        scanf("%d",&arr[i]);
        maxsum += arr[i];
    }
    int l = 0 , r = maxsum;
    int ans = 1e9+1;
    while(l <= r){
        int m = (l+r)/2;
        int totalroom = 1;
        int sumnow = 0;
        int tempmax = 0;
        for(int i = 0 ; i < n ; i ++){
            if(sumnow+arr[i] <= m)sumnow+=arr[i];
            else{
                sumnow = arr[i];
                totalroom ++;
            }
            if(sumnow > tempmax)tempmax = sumnow;
        }
        if(totalroom <= k){
            if(tempmax < ans){
                ans = tempmax;
            }
            r = m - 1;
        }else{
            l = m + 1;
        }
    }
    printf("%d",ans);
    return 0;
}