Accepted
正在同步测试数据，请稍后
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#   状态  耗时  内存占用
#1   Accepted   4ms 332.0 KiB
#2   Accepted   4ms 412.0 KiB
#3   Accepted   4ms 412.0 KiB
#4   Accepted   4ms 412.0 KiB
#5   Accepted   4ms 328.0 KiB
#6   Accepted   4ms 412.0 KiB
#7   Accepted   4ms 412.0 KiB
#8   Accepted   4ms 412.0 KiB
#9   Accepted   4ms 412.0 KiB
#10  Accepted   3ms 412.0 KiB
#11  Accepted   4ms 412.0 KiB
#12  Accepted   3ms 412.0 KiB
#13  Accepted   4ms 412.0 KiB
#14  Accepted   3ms 412.0 KiB
#15  Accepted   5ms 412.0 KiB
#16  Accepted   4ms 412.0 KiB
#17  Accepted   4ms 412.0 KiB
#18  Accepted   4ms 412.0 KiB
#19  Accepted   4ms 368.0 KiB
#20  Accepted   4ms 360.0 KiB
#21  Accepted   4ms 412.0 KiB
#22  Accepted   4ms 412.0 KiB
#23  Accepted   4ms 412.0 KiB
#24  Accepted   4ms 372.0 KiB
#25  Accepted   4ms 340.0 KiB
#26  Accepted   4ms 412.0 KiB
#27  Accepted   4ms 412.0 KiB
#28  Accepted   4ms 312.0 KiB
#29  Accepted   4ms 412.0 KiB
#30  Accepted   4ms 412.0 KiB
#31  Accepted   4ms 376.0 KiB
#32  Accepted   4ms 328.0 KiB
#33  Accepted   4ms 412.0 KiB
#34  Accepted   4ms 352.0 KiB
#35  Accepted   4ms 320.0 KiB
#36  Accepted   4ms 412.0 KiB
#37  Accepted   4ms 412.0 KiB
#38  Accepted   4ms 420.0 KiB
#39  Accepted   4ms 412.0 KiB
#40  Accepted   4ms 328.0 KiB
#41  Accepted   3ms 412.0 KiB
#42  Accepted   4ms 412.0 KiB
#43  Accepted   3ms 412.0 KiB
#44  Accepted   3ms 412.0 KiB
#45  Accepted   4ms 412.0 KiB
#46  Accepted   4ms 312.0 KiB
#47  Accepted   4ms 412.0 KiB
#48  Accepted   4ms 412.0 KiB
#49  Accepted   4ms 328.0 KiB
#50  Accepted   4ms 412.0 KiB

跑的飞快

#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define yh ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
int l,r,cnt=0;
void c(int x)
{
    while(x>0)
    {
        if(x%10==2)cnt++;
        x/=10;
    }
}
int main()
{
    //   freopen("D:\\Vijos\\Input\\input0.txt","r",stdin);
    // freopen("D:\\Vijos\\Output\\output0.txt","w",stdout);
    yh;
    cin>>l>>r;
    for(int i = l;i <= r;i++)c(i);
    cout<<cnt;
    return 0;
}