CodeForces-508A~D篇 div.2

链接：https://codeforc.es/contest/1038

A题：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
#define PI acos(-1.0)
typedef pair<int,int> P;
const int INF=0x3f3f3f3f;
map<int,int> mp;
int a[100010];
int main()
{
    ios::sync_with_stdio(false);
    int n,k;
    string s;
    cin>>n>>k;
    cin >> s;
   int len = 0;
   int ans = INF;
   for(int i=0;i<n;i++) a[i] = s[i] - 'A',mp[a[i]]++;
   for (int i = 0; i < k; i++) ans = min(ans, mp[i]);
   cout << ans * k << endl;
    
    return 0;
}

B题：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
#define PI acos(-1.0)
typedef pair<int,int> P;
const int maxn=0x3f3f3f3f;

int main()
{
    ios::sync_with_stdio(false);
    int n;
    cin>>n;
    if(n<=2) cout<<"No"<<endl;
    else 
    {
        cout<<"Yes"<<endl;
        cout<<n-(n+1>>1);
        for(int i=2;i<=n;i+=2) cout<<" "<<i;
        cout<<endl;
        cout<<(n+1>>1);
        for(int i=1;i<=n;i+=2) cout<<" "<<i;
        cout<<endl;
        
    }
    return 0;
}

C题：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
#define PI acos(-1.0)
typedef pair<int,int> P;
const int INF=0x3f3f3f3f;
const int maxn=1e6+10;
int n;
LL a[maxn],b[maxn],sum1,sum2;
int main()
{
    ios::sync_with_stdio(false);
    cin>>n;
    sum1=sum2=0;
    for(int i=1;i<=n;i++) cin>>a[i];
    for(int i=1;i<=n;i++) cin>>b[i];
    sort(a+1,a+1+n); sort(b+1,b+1+n);
    //for(int i=1;i<=n;i++) cout<<a[i]<<" "<<b[i]<<endl;
    int flag1=n,flag2=n;
    while(1)
    {
        if(a[flag1]<=b[flag2]) flag2--;
        else sum1+=a[flag1],flag1--;
        if(flag2==0)
        {
            sum1+=a[flag1];
            break;
        }
        else if(flag1==0)
        {
            sum2+=b[flag2];
            break;
        }
        if(b[flag2]<=a[flag1]) flag1--; 
        else sum2+=b[flag2],flag2--;
        if(flag2==0)
        {
            sum1+=a[flag1];
            break;
        }
        else if(flag1==0)
        {
            sum2+=b[flag2];
            break;
        }
    }
    cout<<sum1-sum2<<endl;
    return 0;
}

D题：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
#define PI acos(-1.0)
typedef pair<int,int> P;
const int maxn=5e5+10;
int n;
LL a[maxn];
int main()
{
    ios::sync_with_stdio(false);
    
    cin>>n;
    for(int i=1;i<=n;i++) cin>>a[i];
    if(n==1) cout<<a[1]<<endl;
    else
    {
        sort(a+1,a+1+n);
        LL ans=0;
        ans=abs(a[1]-a[n]);
        for(int i=2;i<n;i++) ans=ans+abs(a[i]);
        cout<<ans<<endl;
    }
    
    return 0;
}