#include <iostream>
#include<cstring>
using namespace std;
int main()
{
char a[1005];
int len,i,sum=0;
gets(a);
len=strlen(a);
for(i=0;i<=len-1;i++){
sum++;
if(a[i+1]!=a[i]){
if(sum==1){
printf("%c",a[i]);
sum=0;
}
else{
printf("%d%c",sum,a[i]);
sum=0;
}
}
}
}

https://blog.csdn.net/weixin_42807063/article/details/91414714

问题解决的话，请点采纳

#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
string shuzi(int n) {
    string s="";
    while(n) {
        s.push_back(n%10+'0');
        n/=10;
    }
    reverse(s.begin(),s.end());
    return s;
}
string compressString(string S) {
    if(!S.size())
        return "";
    string s="";
    s.push_back(S[0]);
    for(int i=1; i<S.size(); i++) {
        int t=1;
        while(i<S.size()&&S[i]==s[s.size()-1]) {
            i++;
            t++;
        }
        s+=shuzi(t);
        if(i<S.size())
            s.push_back(S[i]);
    }
    if(s[s.size()-1]<'0'||s[s.size()-1]>'9')
        s.push_back('1');
    return s.size()<S.size()?s:S;
}
int main() {
    string s;
    cin>>s;
    cout<<compressString(s);
    return 0;
}