http://codeforces.com/problemset/problem/348/A
题意:有n个人,在玩一个游戏,游戏表示每局都必须有个管理员参加
告诉你,每个人想当多少局玩家,然后让你求,最少多少局游戏,才能满足题意!
C++版本一
题解:贪心+公式
/*
*@Author: STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
#define endl "\n"
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=100000+10;
const int M=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,p,l,r,u,v;
ll ans,cnt,flag,temp,sum;
ll a[N];
char str;
struct node{};
int main()
{
#ifdef DEBUG
freopen("input.in", "r", stdin);
//freopen("output.out", "w", stdout);
#endif
//ios::sync_with_stdio(false);
//cin.tie(0);
//cout.tie(0);
//scanf("%d",&t);
//while(t--){
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%I64d",&a[i]),sum+=a[i],ans=max(a[i],ans);
n--;
temp=sum/n;
if(sum%n)temp++;
cout<<max(ans,temp)<<endl;
//}
#ifdef DEBUG
printf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC);
#endif
//cout << "Hello world!" << endl;
return 0;
}
C++版本二
题解:二分
如果可以进行游戏,那么必定每次游戏都会有一个人当裁判。所以判断是否可以进行游戏的条件就是检查对于n次游戏,是否都有n个人充当裁判。
/*
*@Author: STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
#define endl "\n"
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=100000+10;
const int M=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const ll INF = 0x3f3f3f3f3f3f3f;
int t,n,m,k,p;
ll l,r,u,v;
ll ans,cnt,flag,temp,sum;
ll a[N];
bool sloved(ll num){
ll cnt=0;
for(int i=1;i<=n;i++){
if(num<a[i])return false;
cnt+=num-a[i];
}
return num<=cnt;
}
int main()
{
#ifdef DEBUG
freopen("input.in", "r", stdin);
//freopen("output.out", "w", stdout);
#endif
//ios::sync_with_stdio(false);
//cin.tie(0);
//cout.tie(0);
//scanf("%d",&t);
//while(t--){
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%I64d",&a[i]);
l=0;
r=1e12;
while(l<=r){
ll mid=(l+r)>>1;
if(sloved(mid)){
ans=mid;
r=mid-1;
}else{
l=mid+1;
}
}
cout<<ans<<endl;
//}
#ifdef DEBUG
printf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC);
#endif
//cout << "Hello world!" << endl;
return 0;
}