这道题确实看着让人不由自主的地想狂写if语句，但是，大可不必。 因为上限9999999999=10^10*9.9,下限10000=10^5，所以只需要判断字符串string类型长度的大小即可，精华部分如下：

string a; #定义字符串类型 a
int p=0; 
cin>>a;
 p=a.length();/*求字符串长度，
也可以用strlen和size替代*/
 }

下面部分建议用switch语句判断，毕竟if语句的可读性出了名的不行。 注意： ****string类型的代码在cstring里（如果是万能的头文件，当我没说）！

#include <bits/stdc++.h>
using namespace std;
int main()
{
    long long n;
    cin >> n;
    if (n > 999999999)
    {
        cout << "shi yi";
    }
    else if (n > 99999999)
    {
        cout << "yi";
    }
    else if (n > 9999999)
    {
        cout << "qian wan";
    }
    else if (n > 999999)
    {
        cout << "bai wan";
    }
    else if (n > 99999)
    {
        cout << "shi wan";
    }
    else if (n > 9999)
    {
        cout << "wan";
    }
    return 0;
}

int n; cin>>n; if (n<100000) { cout<<"wan" ; } else { if (n<1000000) { cout<<"shi wan"; } else { if (n<10000000) { cout<<"bai wan"; } else { if (n<10000000) { cout<<"qian wan"; } else { if (n<1000000000) { cout<<"yi"; } else { cout<<"shi yi"; } } } } } return 0; }

使用if...else if...else语句，判断区间，输出对应的字符串就可以啦

    if(n>=10000&&n<100000){
        cout<<"wan";
    }else if(n>=100000&&n<1000000){
        cout<<"shi wan";
    }else if(n>=1000000&&n<10000000){
        cout<<"bai wan";
    }else if(n>=10000000&&n<100000000){
        cout<<"qian wan";
    }else if(n>=100000000&&n<1000000000){
        cout<<"yi";
    }else{
        cout<<"shi yi";
    }

#include <bits/stdc++.h> using namespace std; int main() { int n; cin >> n; if(n >= 10000 and n < 99999) { cout << "wan" << endl; } if(n >= 100000 and n < 999999) { cout << "shi wan" << endl; } if(n >= 1000000 and n < 9999999) { cout << "bai wan" << endl; } if(n >= 10000000 and n < 99999999) { cout << "qian wan" << endl; } if(n >= 100000000 and n < 999999999) { cout << "yi" << endl; } if(n >= 1000000000 and n < 9999999999) { cout << "shi yi" << endl; } return 0; }

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    cin >> n;

    if (n >= 1000000000)
    {
        cout << "shi yi";
    }
    else if (n >= 100000000)
    {
        cout << "yi";
    }
    else if (n >= 10000000)
    {
        cout << "qian wan";
    }
    else if (n >= 1000000)
    {
        cout << "bai wan";
    }
    else if (n >= 100000)
    {
        cout << "shi wan";
    }
    else
    {
        cout << "wan";
    }
    
    return 0;
}

#include <bits/stdc++.h> 
using namespace std;
int main()
{
    int n;
    cin >> n;
    if(n >= 10000 and n < 99999)
    {
        cout << "wan" << endl;
    }
    if(n >= 100000 and n < 999999)
    {
        cout << "shi wan" << endl;
    }
    if(n >= 1000000 and n < 9999999)
    {
        cout << "bai wan" << endl;
    }
    if(n >= 10000000 and n < 99999999)
    {
        cout << "qian wan" << endl;
    }
    if(n >= 100000000 and n < 999999999)
    {
        cout << "yi" << endl;
    }
    if(n >= 1000000000 and n < 9999999999)
    {
        cout << "shi yi" << endl;
    }
    return 0;
}

代码不好编写，记得点赞

int n;
        cin >> n;
        if(n<=99999)
        {
            cout<<"wan";
        }
        if(n<=999999)if(n>=100000)
        {
            cout<<"shi wan";
        }
        if(n<=9999999)if(n>=1000000)
        {
            cout<<"bai wan";
        }
        if(n<=99999999)if(n>=10000000)
        {
            cout<<"qian wan";
        }
        if(n<=999999999)if(n>=100000000)
        {
            cout<<"yi";
        }
        if(n<=9999999999)if(n>=1000000000)
        {
            cout<<"shi yi";
        }

#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long n;
    cin>>n;
    if (n/1000000000>0)
        cout<<"shi yi";
    else if (n/100000000>0)
        cout<<"yi";
    else if (n/10000000>0)
        cout<<"qian wan";
    else if (n/1000000>0)
        cout<<"bai wan";
    else if (n/100000>0)
        cout<<"shi wan";
    else
        cout<<"wan";
    return 0;
}

好简单 #include <iostream> using namespace std; int main() { long long n; cin>>n; if(n>=1000000000) { cout<<"shi yi"; } else if(n>=100000000) { cout<<"yi"; } else if(n>=10000000) { cout<<"qian wan"; } else if(n>=1000000) { cout<<"bai wan"; } else if(n>=100000) { cout<<"shi wan"; } else { cout<<"wan"; } return 0; }

#include <iostream>
using namespace std;
int main()
{
    int n;
    cin>>n;
    if( n>10000 && n<=99999 )
    {
        cout << "wan";
        return 0;
    }
    else if(n>100000 && n<=999999)
    {
        cout << "shi wan";
        return 0;
    }
    else if(n>1000000 && n<=9999999)
    {
        cout << "bai wan";
        return 0;
    }
    else if(n>10000000 && n<=99999999)
    {
        cout << "qian wan";
        return 0;
    }
    else if(n>100000000 && n<=999999999)
    {
        cout << "yi";
        return 0;
    }
    else if(n>1000000000 && n<=9999999999)
    {
        cout << "shi yi";
        return 0;
    }
}

#include <iostream>
using namespace std;
string a[12]={" "," "," "," ","wan","shi wan","bai wan","qian wan","yi","shi yi"};
int main()
{
    string s;
    cin>>s;
    int len=s.size();
    cout<<a[len-1];
    return 0;
}