牛客CSP-S提高组赛前集训营2 ———— 2019.10.31

比赛链接

期望得分：100+20+20

实际得分：40+20+30

awa  cccc

T1 :基于贪心的思路，然后开始爆搜（雾

那必然是会死的，好吧他就是死了

#include<iostream>
#include<cstdio>
#include<algorithm>
#define int long long
using namespace std;
int n,q,m;
int ans,sum=-1;
int a[400005];
int x,y;
inline int read();
int cha() {
    int ans=-1;
    for(int i=1; i<=n; i++)ans=max(ans,a[i]);
    return ans;
}
signed main() {
    n=read(),m=read(),q=read();
    for(int i=1; i<=n; i++) {
        a[i]=read();
        ans+=a[i];
        sum=max(a[i],sum);
    }
    if(sum*m>=ans)cout<<sum<<"\n";
    else {
        sum=ans/m;
        if(ans%m)sum++;
        cout<<sum<<"\n";
    }
    while(q--) {
        x=read(),y=read();
        ans+=y-a[x];
        if(y<a[x]&&a[x]==sum)a[x]=y,sum=cha();
        a[x]=y;
        if(y>sum)sum=y;
        if(sum*m>=ans)cout<<sum<<"\n";
        else {
            sum=ans/m;
            if(ans%m)sum++;
            cout<<sum<<"\n";
        }
    }
    return 0;
}
inline int read() {
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9') {
        if(ch=='-')w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
        s=(s<<3)+(s<<1)+(ch^48),ch=getchar();
    return s*w;
}

T2:题目倒是没看明白，smg

 

就直接贴了个并查集求连通块个数，，，只拿了20分

 

20分代码(☄⊙ω⊙)☄：

//20分，k=0的情况,若k!=0,直接return 0，毫不犹豫awa
//看我对评测机多好，希望评测机可以对我好一点
#include<iostream>
#include<cstdio>
#include<cmath>
#define int long long
using namespace std;
int N,M,K,ans;
int  pre[1000050];
int find(int a) {
    if(pre[a]!=a) pre[a]=find(pre[a]);
    return pre[a];
}
void join(int x,int y) {
    int fx=find(x),fy=find(y);
    if(fx!=fy) pre[fy]=fx;
}
inline int read() {
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9') {
        if(ch=='-')w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
        s=(s<<3)+(s<<1)+(ch^48),ch=getchar();
    return s*w;
}
signed main() {
    N=read(),M=read(),K=read();
    if(K!=0){
        cout<<M-K+1<<endl;
        return 0;
    }
    for(int i=1; i<=N; i++) pre[i]=i;
    for(int i=1; i<=M; i++) {
        int a,b;
        a=read(),b=read();
        join(a,b);
    }
    for(int i=1; i<=N; i++) if(pre[i]==i) ans++;
    cout<<ans;
    return 0;
}

T3：暴力模拟30分

#include<iostream>
#include<cmath>
#include<cstdio>
#include<cstring>
using namespace std;
const int inf=0x3f3f3f3f;
int n,m,f;
int t,l,r,x,y;
int ans;
int a[100001];
bool vis[100001];
void gai(int l,int r,int x) {
    memset(vis,false,sizeof vis);
    for(int i=l; i<=r; i++)a[i]=x;
    for(int i=1; i<=n; i++)vis[a[i]]=true;
 
}
void cha(int x,int y) {
    if(!vis[x]||!vis[y]) {
        ans=-1;
        return;
    }
    ans=inf;
    for(int i=1; i<=n; i++)
        for(int j=i; j<=n; j++)
            if((a[i]==x&&a[j]==y)||(a[i]==y&&a[j]==x)) {
                ans=min(ans,abs(i-j));
                break;
            }
    if(ans==inf)ans=-1;
}
int lastans;
inline int read() {
    int s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9') {
        if(ch=='-')w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
        s=(s<<3)+(s<<1)+(ch^48),ch=getchar();
    return s*w;
}
int main() {
    n=read(),m=read(),f=read();
    for(int i=1; i<=n; i++)
        a[i]=read(),vis[a[i]]=true;
    for(int i=1; i<=m; i++) {
        t=read();
        if(t==1) {
            l=read(),r=read(),x=read();
            if(f==1)l^=lastans,r^=lastans,x^=lastans;
            gai(l,r,x);
        }
        if(t==2) {
            x=read(),y=read();
            if(f)x^=lastans,y^=lastans;
            cha(x,y);
            cout<<ans<<"\n";
            if(ans==-1)lastans=0;
            else lastans=ans;
        }
    }
    return 0;
}

想要AC代码来这里