Reversals

#include <iostream>
#include <string>
#include <stdio.h>

int main() {
   using namespace std;
   int n = 0;
   int m = 0;
   cin >> n >> m;

   string ln;
   getline(cin, ln);
   getline(cin, ln);

   for (int i = 0; i < m; i++) {
      int a; int b;
      cin >> a >> b;
      a--; b--;

      char tmp = ' ';
      for (int j = a; j <= (b + a)/2; j++) {
         tmp = ln[j];
         ln[j] = ln[b - (j - a)];
         ln[b - (j - a)] = tmp;
      }
   }

   cout << ln << endl;
   return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: TIME LIMIT EXCEEDED