View Compilation Error

0_0_32863712_12557.cpp: In function 'void dfs2()':
0_0_32863712_12557.cpp:39:22: error: 'memset' was not declared in this scope
  memset(C,0,sizeof(C));
                      ^
0_0_32863712_12557.cpp: In function 'long long int Cal(long long int)':
0_0_32863712_12557.cpp:66:22: error: 'memset' was not declared in this scope
  memset(d,0,sizeof(d));
                      ^
0_0_32863712_12557.cpp: In function 'int main()':
0_0_32863712_12557.cpp:78:25: error: 'memset' was not declared in this scope
   memset(dp,0,sizeof(dp));
                         ^