Codeforces Round #436 (Div. 2) A,B,D

A. Fair Game

题目链接：http://codeforces.com/contest/864/problem/A

水题

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<stack>
#include<map>
#include<vector>
#include<set>
using namespace std;
const int MAX=1e5+;
const double eps=1e-;
const double mod=1e9+;
#define INF 0x7fffffff
#define ll long long
#define edl putchar('\n')
#define useit  ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define FOR(i,a,b) for(ll i=a;i<=b;i++)
#define ROF(i,a,b) for(ll i=a;i>=b;i--)
#define mst(a) memset(a,0,sizeof(a))
#define mstn(a,n) memset(a,n,sizeof(a))
#define lowbit(x) x&(-x)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
//struct num{int v,i;}l[MAX],r[MAX];
//bool cmp(const num &x, const num &y){return x.v<y.v;}

int main()
{
    int n,a[MAX],b,t=,s1=,s2=;
    FOR(i,,)a[i]=;
    cin>>n;
    FOR(i,,n)
    {
        cin>>b;
        if(!a[b])
        t++;
        a[b]++;
    }
    if(t==)
    {
        FOR(i,,) if(a[i]){s1=i;break;}
        ROF(i,,) if(a[i]){s2=i;break;}
        if(a[s1]==a[s2]&&s1!=s2)
        cout<<"YES"<<endl<<s1<<" "<<s2<<endl;
        else
        cout<<"NO"<<endl;
    }
    else
    cout<<"NO"<<endl;
}

B. Polycarp and Letters

题目链接：http://codeforces.com/contest/864/problem/B

水题，写太急了，忘了考虑全是小写字母的情况，wa了两发血亏。

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int inf = 1e9+;
const int M = 1e5+;
map<char,int>mp;
int main()
{
    int n,maxx;
    char s[];
    cin>>n;
    for(int i=;i<n;i++)
        cin>>s[i];
    maxx = -inf;
    int ans = ;
    for(char i = 'a';i<='z';i++){
                mp[i] = ;
            }
    for(int i=;i<n;i++){
        if(s[i]>='a'&&s[i]<='z'){
            if(mp[s[i]]==)
            {
                ans++;
                mp[s[i]]=;
            }
        }
        else{
            maxx = max(ans,maxx);
            ans = ;
            for(char i = 'a';i<='z';i++){
                mp[i] = ;
            }
        }
    }
    maxx = max(ans,maxx);
    cout<<maxx<<endl;
    return ;
}

D. Make a Permu！

题目链接：http://codeforces.com/contest/864/problem/D

题目有点水，直接暴力过了。。

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int inf = 1e9+;
const int M = 2e5+;
map<int,int>mp;
int a[M],flag[M];
int main()
{
    int n,maxx,i,j;
    cin>>n;
    maxx = -inf;
    memset(flag,,sizeof(flag));
    int cnt = ;
    for(i=;i<n;i++){
        cin>>a[i];
        mp[a[i]]++;
        if(mp[a[i]]>)
        cnt++;
        maxx = max(a[i],maxx);
    }
    int l=;
    for(i=;i<n;i++){
        if(mp[a[i]]>){
            for(j=l+;j<=M;j++){
            if(mp[j]==){
                  mp[j]==;
                  l = j;break;
             }
           }
           //cout<<l<<endl;
            if(l<a[i]){
                   //cout<<mp[a[i]]<<endl;
                mp[a[i]]-=,a[i]=l;  //之前这里先替换再标记。搞得wa了一发，血亏。。还好学长出了发神样例查到了
                //cout<<mp[a[i]]<<endl;
            }
            else{
                if(flag[a[i]]==){
                    mp[a[i]]--,a[i]=l;
                }
                else{
                    mp[l]==;l--;
                    flag[a[i]] = ;
                }
            }
        }
    }
    cout<<cnt<<endl;
    for(i=;i<n;i++){
        cout<<a[i]<<" ";
    }
    cout<<endl;
    return ;
}