POJ - 3104 Drying

/*********************************************************
*            ------------------                          *
*   author AbyssalFish                                   *
**********************************************************/
#include<cstdio>
#include<iostream>
#include<string>
#include<cstring>
#include<queue>
#include<vector>
#include<stack>
#include<vector>
#include<map>
#include<set>
#include<algorithm>
#include<cmath>
using namespace std;

const int maxn = 1e5;
int n, a[maxn], k;

bool P(int t)
{
int c = 0;
for(int i = 0; i < n; i++){
if(a[i] > t){
if((c += (a[i]-t-1+k)/k) > t) return false; //2e9
}
}
return true;
}

//#define LOCAL
int main()
{
#ifdef LOCAL
freopen("in.txt","r",stdin);
#endif
while(~scanf("%d",&n)){
for(int i = 0; i < n; i++) scanf("%d",a+i);
scanf("%d",&k);
int lb = 1, ub = *max_element(a,a+n);//1e9;
if(k-- == 1) lb = ub;
while(lb < ub){
int md = (lb+ub)>>1;
P(md) ? ub = md: lb = md+1;
}
printf("%d\n",lb);
}

return 0;
}