Codeforces Round #508 (Div. 2)【A,B,C,D】【实验室日常周赛训练】

#include<bits/stdc++.h>

using namespace std;
#define inf 0x3f3f3f3f3f3f
#define int long long 
int vis[150];
signed main(){
    int n,k;
    cin>>n>>k;
    string str;
    cin>>str;
    map<int,int> mp;
    int sum=0;
    for(int i=0;i<str.size();i++){
        if(!mp[str[i]-'A']){
            mp[str[i]-'A']=1;
            sum++;
        }
        vis[str[i]-'A']++;
    }
    if(sum==k){
        int ans=inf;
        for(int i=0;i<k;i++){
            ans=min(ans,vis[i]);
        }
        //cout<<ans<<'
';
        cout<<ans*k;
    }else{
        cout<<"0";
    }
    return 0;
} 

 思路：猜了一个想法，就过了。

#include<bits/stdc++.h>

using namespace std;
#define int long long

signed main(){
    int n;
    cin>>n;
    if(n==1||n==2){
        cout<<"No";return 0; 
    }
    printf("Yes
");
    int m=n/2;
    if(n%2){
        int s1=0,s2=0;
        printf("%lld ",1+m);
        for(int i=1;i<=n;i+=2){
            printf("%lld ",i);
            s1+=i;
        }
        printf("
");
        printf("%lld ",m);
        for(int i=2;i<=n;i+=2){
            printf("%lld ",i);
            s2+=i;
        }
        printf("
");
    //    cout<<__gcd(s1,s2)<<'
';
    }else{
        int s1=0,s2=0;
        printf("%lld ",m);
        for(int i=1;i<=n;i+=2){
            printf("%lld ",i);
            s1+=i;
        }
        printf("
");
        printf("%lld ",m);
        for(int i=2;i<=n;i+=2){
            printf("%lld ",i);
            s2+=i;
        }
        printf("
");
    //    cout<<__gcd(s1,s2)<<'
';
    }
    return 0;
}
/*

*/

 思路：贪心+模拟【判断应该加自己和移除对手的值哪一个大。优先队列维护最大值】

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define N 10050005
priority_queue <int,vector<int>,less<int> >q1;
priority_queue <int,vector<int>,less<int> >q2;
int a[N];
int b[N];
signed main(){
    int n;cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        q1.push(a[i]);
    }
    for(int i=1;i<=n;i++){
        cin>>b[i];
        q2.push(b[i]);
    }
    int suma=0,sumb=0;
    int now=0;
    while(1){
        now++;
        if(q1.empty()&&q2.empty()){
            break;
        }
        int t1=0,t2=0;
        if(now%2){//A
            if(!q1.empty()&&!q2.empty()){
                t1=q1.top();
                t2=q2.top();
                if(t1>t2){
                    q1.pop();
                    suma+=t1;
                }else{
                    q2.pop();
                }
            }else if(q1.empty()&&!q2.empty()){
                q2.pop();
            }else if(!q1.empty()&&q2.empty()){
                suma+=q1.top();
                q1.pop();
            
            }
            
        }else{
            if(!q1.empty()&&!q2.empty()){
                t1=q1.top();
                t2=q2.top();
                if(t2>t1){
                    q2.pop();
                    sumb+=t2;
                }else{
                    q1.pop();
                }
            }else if(q1.empty()&&!q2.empty()){
                sumb+=q2.top();
                q2.pop();
            }else if(!q1.empty()&&q2.empty()){
                q1.pop();
            }
            
        }
    }
    //cout<<suma<<" "<<sumb<<'
';
    cout<<suma-sumb;
    return 0;
}

#include<bits/stdc++.h>
 
using namespace std;
#define int long long
#define inf 1<<30
#define N 10005000
int arr[N];
signed main(){
    int n;cin>>n;
    if(n==1)
    {
        int qwq;
        cin>>qwq;
        cout<<qwq<<endl;return 0;
    }
    int flag1=0;int flag2=0;
    int sum1=0;int minx=inf;
    for(int i=1;i<=n;i++) {
        cin>>arr[i];
        sum1+=abs(arr[i]);
        if(arr[i]<0){
            flag1=1;
        }else if(arr[i]>0){
            flag2=1;
        }
        minx=min(minx,abs(arr[i]));
    }
    if(flag1&&flag2){
        cout<<sum1;
    }else{
        cout<<sum1-abs(minx)*2;
    }
    return 0;
}