Educational Codeforces Round 131 (Rated for Div. 2)

 Problem - A - Codeforces

#include
#define debug0(x) cout << "debug0: " << x << endl
#define fr(t, i, n) for (int i = t; i < n; i++)
#define first fi
#define second se
using namespace std;

typedef long long LL;
typedef pair PII;


const int N = 2e5+10;
int a[N];

void solve(){
    int zero = 0,one = 0;
    for(int i = 0;i < 4;i ++)
    {
        cin >> a[i];
        if(a[i])one = 1;
        else zero = 1;
    }

    cout << !zero + one << endl;
}

int main()
{

	int T;cin >> T;
	
	while(T--){
		solve();
	}
	return 0;
}

Problem - C - Codeforces

        经典二分题目

#include
#define debug0(x) cout << "debug0: " << x << endl
#define fr(t, i, n) for (int i = t; i < n; i++)
#define first fi
#define second se
using namespace std;

typedef long long LL;
typedef pair PII;

const int N = 2e5+10;
int a[N];

void solve(){
    memset(a,0,sizeof a);
    int n,m;cin >> n >> m;
    int l = 1,r = 0;
    for(int i = 0;i < m;i ++){
        int t;cin >> t;
        a[t]++;
        r = max(r,a[t]);
    }
    
    while(l < r)
    {
        //cout << l << " " << r << endl;
        int mid = (l+r)>>1;
        LL lei = 0,mor = 0;
        for(int i = 1;i <= n;i ++){
            if(a[i] < mid)lei += (mid - a[i])/2;
            else mor += a[i] - mid;
        }
        /*
        if(mor == lei)
        {
            cout << mid << endl;
            return ;
        }
        */
        if(mor > lei)l = mid+1;
        else r = mid;
    }
    cout << l << endl;
}

int main()
{
	/*
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	*/
	int T;cin >> T;
	
	while(T--){
		solve();
	}
	return 0;
}