View Compilation Error

0_0_33910983_2787.cpp: In function 'void calcTimeArea(timeArea*, timeArea, double, double)':
0_0_33910983_2787.cpp:47:42: error: 'memset' was not declared in this scope
     memset(pTimeArea, 0, sizeof(timeArea));
                                          ^
0_0_33910983_2787.cpp: In function 'double percentage(double)':
0_0_33910983_2787.cpp:82:56: error: 'malloc' was not declared in this scope
     pSM = (timeArea*) malloc(MAX_LEN * sizeof(timeArea));
                                                        ^
0_0_33910983_2787.cpp:85:46: error: 'memset' was not declared in this scope
     memset(pSM, 0, MAX_LEN * sizeof(timeArea));    
                                              ^
0_0_33910983_2787.cpp:105:17: error: 'free' was not declared in this scope
     free(pMerged);
                 ^