View Compilation Error

0_0_37147958_31704.cpp: In function 'void init()':
0_0_37147958_31704.cpp:22:25: error: 'memset' was not declared in this scope
     memset(C,0,sizeof(C));
                         ^
0_0_37147958_31704.cpp: In function 'int main()':
0_0_37147958_31704.cpp:38:29: error: 'memset' was not declared in this scope
         memset(w,0,sizeof(w));
                             ^