View Compilation Error

0_0_36090338_8355.cpp: In function 'long long int finalenergy(monster*, int)':
0_0_36090338_8355.cpp:180:48: error: 'memset' was not declared in this scope
     memset(finalenerg,0,(mstnum+10)* sizeof(ll));
                                                ^
0_0_36090338_8355.cpp: In function 'long long int* simplefinal(monster*, int)':
0_0_36090338_8355.cpp:250:48: error: 'memset' was not declared in this scope
     memset(finalenerg,0,(mstnum+10)* sizeof(ll));
                                                ^