View Compilation Error

0_0_21947330_9182.cpp: In function 'void spfa(int, int)':
0_0_21947330_9182.cpp:32:31: error: 'memset' was not declared in this scope
     memset(vis, 0, sizeof(vis));
                               ^
0_0_21947330_9182.cpp: In function 'int main()':
0_0_21947330_9182.cpp:63:31: error: 'memset' was not declared in this scope
         memset(H, 0, sizeof(H));
                               ^