View Compilation Error

0_0_13808559_30611.cpp: In function 'void bfs1(int, int)':
0_0_13808559_30611.cpp:57:29: error: 'memset' was not declared in this scope
     memset(ans,0,sizeof(ans)); 
                             ^
0_0_13808559_30611.cpp: In function 'void bfs2(int, int)':
0_0_13808559_30611.cpp:129:29: error: 'memset' was not declared in this scope
     memset(ans,0,sizeof(ans)); 
                             ^