题解NOIP201601&02

Posted 2020-08-20

NOIP201601

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>

using namespace std;

inline int read()
{
    int x=0,f=1;char ch=getchar();
    for(;!isdigit(ch);ch=getchar()) if(ch==‘-‘) f=-1;
    for(;isdigit(ch);ch=getchar()) x=x*10+ch-‘0‘;
    return x*f;
}

int n,ans=1000000;

int main()
{
    n=read();
    for(int i=0;i<3;i++)
    {
        int a=read(),b=read();
        if( n % a == 0) ans=min(ans,(n/a)*b);
        else ans=min(ans,(n/a+1)*b);
    }
    printf("%d\n",ans);
}

NOIP201602

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>

using namespace std;

inline int read()
{
    int x=0,f=1;char ch=getchar();
    for(;!isdigit(ch);ch=getchar()) if(ch==‘-‘) f=-1;
    for(;isdigit(ch);ch=getchar()) x=x*10+ch-‘0‘;
    return x*f;
}

int n,m,a[8],b[8],now,ans;

bool rn(int year)
{
    if( (year % 4 == 0 && year % 100 != 0) || year % 400 == 0 ) return true;
    return false;
}

int main()
{
    n=read(),m=read();
    while(n > 0)
    {
        a[now++]=n%10;
        n/=10;
    }
    now=0;
    while(m > 0 )
    {
        b[now++]=m%10;
        m/=10;
    }
    
    for(int i=0;i<4;i++) swap(a[i],a[7-i]),swap(b[i],b[7-i]);
    
    int 
    
        nyear=a[0]*1000+a[1]*100+a[2]*10+a[3],
        nmonth=a[4]*10+a[5]-1,
        nday=a[6]*10+a[7],
        
        myear=b[0]*1000+b[1]*100+b[2]*10+b[3],
        mmonth=b[4]*10+b[5]-1,
        mday=b[6]*10+b[7],
        
        month[12]={31,0,31,30,31,30,31,31,30,31,30,31};
    
    for(int i=nyear;i<=myear;i++)
    {
        if( rn(i)) month[1]=29;
        else month[1]=28;
        
        int nowy[4],tmp=i;now=0;
        while( tmp > 0)
        {
            nowy[now++]=tmp%10;
            tmp/=10;
        }
        for(int j=0;j<2;j++) swap(nowy[j],nowy[3-j]);
        
        
        
        int 
            dd=nowy[0]+nowy[1]*10,
            mm=nowy[2]+nowy[3]*10-1;
        
        if( dd > month[mm] || dd <= 0 || mm >= 12 || mm < 0 ) continue;
        
        if( i == nyear )
        {
            if( mm < nmonth || mm > 13 ) continue;
            if( dd < nday || dd > month[nmonth] ) continue;
        }
        else if( i == myear )
        {
            if( mm > mmonth) continue;
            if( dd < nday || dd > month[mmonth] ) continue;
        }
        
        ans++;
        month[1]=0;
    }
    
    printf("%d\n",ans);
}