View Compilation Error

0_0_30580225_15919.cpp: In function 'int main()':
0_0_30580225_15919.cpp:22:26: error: 'strcmp' was not declared in this scope
     if (strcmp(a[i], a[j]) == 0)
                          ^
0_0_30580225_15919.cpp:32:22: error: 'strcpy' was not declared in this scope
     strcpy(a[0], a[i]);
                      ^