View Compilation Error

0_0_20682080_31508.cpp: In function 'int main()':
0_0_20682080_31508.cpp:6:63: error: 'memset' was not declared in this scope
 while(t--) { int n,m;scanf("%d%d",&n,&m); memset(c,0,sizeof(c));  
                                                               ^
0_0_20682080_31508.cpp:14:3: error: 'return0' was not declared in this scope
 } return0;
   ^