题解 | #表示数字#

#include <bits/stdc++.h>
#include <cctype>
#include <vector>
using namespace std;

int main() {
    string s;
    cin>>s;
    vector<char> v;
    for (int i=0; i<s.size();i++) {
        if(isdigit(s[i])&&!isdigit(s[i+1])&&!isdigit(s[i-1])){
            v.push_back('*');
            v.push_back(s[i]);
            v.push_back('*');
        }else if (isdigit(s[i])&&isdigit(s[i+1])&&!isdigit(s[i-1])) {
            v.push_back('*');
            v.push_back(s[i]);
        }else if (isdigit(s[i])&&!isdigit(s[i+1])&&isdigit(s[i-1])) {            
            v.push_back(s[i]);  
            v.push_back('*');          
        }
        else {
            v.push_back(s[i]);
        }
    }

    for (int i=0; i<v.size();i++) {
        cout<<v[i];
    }
}
// 64 位输出请用 printf("%lld")