How to use string.substr() function?
c++, string, substring
Solution
If I am correct, the second parameter of `substr()` should be the length of the substring. How about
b = a.substr(i,2);
?
Problem
I want to make a program that will read some number in string format and output it like this: if the number is 12345 it should then output 12 23 34 45 . I tried using the substr() function from the c++ string library, but it gives me strange results - it outputs 1 23 345 45 instead of the expected result. Why ? ``` #include <iostream> #include <string> #include <cstdlib> using namespace std; int main(void) { string a; cin >> a; string b; int c; for(int i=0;i<a.size()-1;++i) { b = a.substr(i,i+1); c = atoi(b.c_str()); cout << c << " "; } cout << endl; return 0; } ```