View Compilation Error

0_0_20061322_17059.cpp: In function 'int main()':
0_0_20061322_17059.cpp:7:14: error: 'itoa' was not declared in this scope
   itoa(-m,a,n);
              ^
0_0_20061322_17059.cpp:11:13: error: 'itoa' was not declared in this scope
   itoa(m,a,n);
             ^