View Compilation Error

0_0_35997858_10722.cpp: In function 'Matrix mat_mul(Matrix, Matrix, int)':
0_0_35997858_10722.cpp:62:36: error: 'memset' was not declared in this scope
  memset(ans.mat, 0, sizeof(ans.mat));
                                    ^
0_0_35997858_10722.cpp: In function 'Matrix quick_power(Matrix, int, int)':
0_0_35997858_10722.cpp:74:42: error: 'memset' was not declared in this scope
  memset(result.mat, 0, sizeof(result.mat));
                                          ^