20170905

水题：

T1
Kirill And The Game

#include<cstdio>
int main()
{
    bool flag=false;
    long long l,r,x,y,k;
    scanf("%lld%lld%lld%lld%lld",&l,&r,&x,&y,&k);
    for(int i=x;i<=y;i++)
        if(k*i>=l&&k*i<=r)
        {
            flag=true;
            break;
        }
    if(flag==false)
        printf("NO");
    else
        printf("YES");
    return 0;
}

错误原因：忽略了a和b都是整数

错误代码：

#include<cstdio>
int main()
{
    long long l,r,x,y,k;
    scanf("%lld%lld%lld%lld%lld",&l,&r,&x,&y,&k);
    if(k*y>=l&&k*x<=r)
        printf("YES");
    else
        printf("NO");
    return 0;
}

T2

Gleb And Pizza

#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
double d,r;
int ans,n;
int main()
{
    double x,y,r,p,p2,r2;
    scanf("%lf%lf",&r,&d);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%lf%lf%lf",&x,&y,&r2);
        p=sqrt(x*x+y*y);
        p2=min(p-r+d,r-p);
        if(r2<=p2)
            ans++;
    }
    printf("%d",ans);
    return 0;
}

智商题

T3

Ilya And The Tree

T4

Mike and gcd problem

T5

Bank Hacking