https://pintia.cn/problem-sets/994805046380707840/exam/problems/994805143738892288
#include<bits/stdc++.h>
using namespace std;
int a[10010];
int main()
{
string n;
cin>>n;
for(int i=0;i<n.length();i++)
{
a[n[i]-'0']++;
}
for(int i=0;i<10;i++)
{
if(a[i]!=0){
printf("%d:%d\n",i,a[i]);
}
}
return 0;
}