noip2014普及组

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
inline int read(){
    int t=1,num=0;char c=getchar();
    while(c>‘9‘||c<‘0‘){if(c==‘-‘)t=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){num=num*10+c-‘0‘;c=getchar();}
    return num*t;
}
int n,a[101],ans=0;
int main()
{
    n=read();
    for(int i=1;i<=n;i++)a[i]=read();
    for(int i=1;i<=n;i++){
        int t=0;
        for(int j=1;j<n;j++){
            for(int k=j+1;k<=n;k++){
                if(a[i]==a[j]+a[k])
                    t=1;
            }
        }
        if(t)ans++;
    }
    printf("%d\n",ans);
    return 0;
}

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
int main()
{
    pair<int,int> q;
    double a,b;int l;
    double cha,num,xiao=99999;
    cin>>a>>b>>l;
    num=a/b;
    for(double i=1;i<=l;i=i+1){
        for(double j=1;j<=l;j=j+1){
            cha=i/j;
            if(xiao>cha-num&&cha>=num) {q.first=int(i);q.second=int(j);xiao=cha-num;} 
        }
    }
    cout<<q.first<<" "<<q.second;
    return 0;
} 

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
inline int read(){
    int t=1,num=0;char c=getchar();
    while(c>‘9‘||c<‘0‘){if(c==‘-‘)t=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){num=num*10+c-‘0‘;c=getchar();}
    return num*t;
}
int n,a,b,ans=0;
int main()
{
    n=read();a=read();b=read();
    int x=1,y=n;
    while(a>x&&b>x&&a<y&&b<y){
        ans+=4*(n-1);
        x++;y--;n-=2;
    }
    if(a==x)ans+=b-x+1;
    else if(a==y)ans+=2*(n-1)+y-b+1;
    else if(b==x)ans+=3*(n-1)+y-a+1;
    else ans+=n-1+a-x+1;
    printf("%d\n",ans);
    return 0;
}

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
inline int read(){
    int t=1,num=0;char c=getchar();
    while(c>‘9‘||c<‘0‘){if(c==‘-‘)t=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){num=num*10+c-‘0‘;c=getchar();}
    return num*t;
}
inline int min(int a,int b){return a<b?a:b;}
inline int abs(int a){return a>0?a:-a;}
int n,m,r,c,ans=0x7fffffff;
int a[18][18],f[18][18];
int w[18],v[18][18],rec[18];
void dp(){
    memset(f,127,sizeof(f));
    memset(w,0,sizeof(w));
    memset(v,0,sizeof(v));
    for(int i=1;i<=m;i++)
        for(int j=1;j<r;j++)
            w[i]+=abs(a[rec[j]][i]-a[rec[j+1]][i]);
    for(int i=1;i<=m;i++)
        for(int j=i+1;j<=m;j++)
            for(int k=1;k<=r;k++)
                v[i][j]+=abs(a[rec[k]][i]-a[rec[k]][j]);
    f[0][0]=0;
    for(int i=1;i<=c;i++)
        for(int j=i;j<=m;j++)
            for(int k=0;k<j;k++)
                f[i][j]=min(f[i-1][k]+w[j]+v[k][j],f[i][j]);
    for(int i=c;i<=m;i++)
        ans=min(ans,f[c][i]);
}
void dfs(int x,int y){
    if(y>r){dp();return;}
    if(x>n)return;
    for(int i=x;i<=n;i++){
        rec[y]=i;dfs(i+1,y+1);
    }
}
int main()
{
    n=read();m=read();r=read();c=read();
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            a[i][j]=read();
    dfs(1,1);printf("%d\n",ans);   
    return 0; 
}