View Compilation Error

0_0_20775683_6803.cpp: In function 'void xmult(int (*)[66], int (*)[66], int)':
0_0_20775683_6803.cpp:13:26: error: 'memset' was not declared in this scope
    memset( c,0,sizeof(c) );
                          ^
0_0_20775683_6803.cpp: In function 'void init()':
0_0_20775683_6803.cpp:49:30: error: 'memset' was not declared in this scope
  memset( temp,0,sizeof(temp) );
                              ^