View Compilation Error

0_0_36425438_10792.cpp: In constructor 'matrix::matrix()':
0_0_36425438_10792.cpp:23:25: error: 'memset' was not declared in this scope
   memset(q, 0, sizeof(q));
                         ^
0_0_36425438_10792.cpp: In function 'int main()':
0_0_36425438_10792.cpp:63:26: error: 'memset' was not declared in this scope
   memset(pp, 0, sizeof pp);
                          ^