Question

How to delete the first digit from a number in C++

Answer 1

#include <iostream>
#include <sstream> 

int main() {
    int n = 853271;
    auto s = std::to_string(n);
    
    s[0] = '0';
    std::stringstream ss(s); 
    ss >> n;
     
    std::cout << n;
}



/*
run:

53271

*/

 

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Answer 2

#include <iostream>
#include <cmath> 
 
int main() {
    int n = 853271;
    
    std::cout << (int)log10(n) << "\n";
    std::cout << (int)pow(10, (int)log10(n)) << "\n";
          
    n = n % (int)pow(10, (int)log10(n));
      
    std::cout << n;
}
 
 
 
 
/*
run:
 
5
100000
53271
 
*/

 

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