Codeforces Round #392 (Div. 2)

这一场有点坑

A题，求最大值之后相减

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-7;
const int N=1000+10,maxn=500+100,inf=0x3f3f3f;

int a[N];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n,maxx=-1,ans=0;
    cin>>n;
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        maxx=max(a[i],maxx);
    }
    for(int i=0;i<n;i++)
        ans+=maxx-a[i];
    cout<<ans<<endl;
    return 0;
}
/********************

********************/

B，暴力dfs，注意剪枝

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-7;
const int N=1000+10,maxn=500+100,inf=0x3f3f3f;

char p[4]={'R','B','Y','G'};
string ans;
bool ok(string s)
{
    for(int i=0;i+3<s.size();i++)
    {
        int rr=0,bb=0,yy=0,gg=0;
        for(int j=0;j<4;j++)
        {
            if(s[i+j]=='R')rr++;
            else if(s[i+j]=='B')bb++;
            else if(s[i+j]=='Y')yy++;
            else gg++;
        }
        if(rr!=1||gg!=1||yy!=1||bb!=1)return 0;
    }
    return 1;
}
void dfs(int x,string t)
{
   // cout<<t<<endl;
    if(x==t.size())
    {
        if(ok(t))ans=t;
        return ;
    }
    if(t[x]=='!')
    {
        for(int i=0;i<4;i++)
        {
            t[x]=p[i];
            if(x>=3)
            {
                int rr=0,bb=0,yy=0,gg=0;
                for(int j=0; j<4; j++)
                {
                    if(t[x-j]=='R')rr++;
                    else if(t[x-j]=='B')bb++;
                    else if(t[x-j]=='Y')yy++;
                    else gg++;
                }
                if(rr!=1||gg!=1||yy!=1||bb!=1)continue;
            }
            dfs(x+1,t);
        }
    }
    else dfs(x+1,t);
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin>>s;
    int kr=0,kb=0,ky=0,kg=0;
    dfs(0,s);
    for(int i=0;i<s.size();i++)
    {
        if(s[i]=='!')
        {
            if(ans[i]=='R')kr++;
            else if(ans[i]=='B')kb++;
            else if(ans[i]=='Y')ky++;
            else if(ans[i]=='G')kg++;
        }
    }
    cout<<kr<<" "<<kb<<" "<<ky<<" "<<kg<<endl;
    return 0;
}
/********************
!!!!YGRB
YGR!YGRB
********************/

C分类讨论，O（1）模拟

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-7;
const int N=1000+10,maxn=500+100,inf=0x3f3f3f;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll n,m,k,x,y;
    cin>>n>>m>>k>>x>>y;
    if(n==1)
    {
        if(k%m==0)cout<<k/m<<" "<<k/m<<" "<<k/m<<endl;
        else cout<<k/m+1<<" "<<k/m<<" "<<(k%m>=y?k/m+1:k/m)<<endl;
        return 0;
    }
    if(n==2)
    {
        ll s=k/(2*m),p=k%(2*m),ans;
        if(p>=(x-1)*m+y)ans=s+1;
        else ans=s;
        if(p==0)cout<<s<<" "<<s<<" "<<ans<<endl;
        else cout<<s+1<<" "<<s<<" "<<ans<<endl;
        return 0;

    }
    ll s=k/((2*n-2)*m),p=k%((2*n-2)*m);
    ll maxx,minn,ans;
    if(m<p&&p<=n*m)maxx=s*2+1;
    else if(p<=m)maxx=s*2;
    else if(p>n*m)maxx=s*2+2;
    maxx=max(maxx,1ll);
    if(p<n*m)minn=s;
    else minn=s+1;
  //  cout<<s<<" "<<p<<endl;
    if(x==1)
    {
        if(p>=y)ans=s+1;
        else ans=s;
    }
    else if(2<=x&&x<=n-1)
    {
        if(p<(x-1)*m+y)ans=s*2;
        else if(p>=(x-1)*m+y&&p<(2*n-x-1)*m+y)ans=s*2+1;
        else ans=s*2+2;
    }
    else
    {
        if(p>=(n-1)*m+y)ans=s+1;
        else ans=s;
    }
    cout<<maxx<<" "<<minn<<" "<<ans<<endl;
    return 0;
}
/********************
47 39 1772512 1 37
********************/