View Compilation Error

0_0_32425285_17920.cpp: In function 'void readData()':
0_0_32425285_17920.cpp:24:32: error: 'memset' was not declared in this scope
     memset(head,-1,sizeof(head));
                                ^
0_0_32425285_17920.cpp: In function 'void dijkstra(int, int (&)[1005])':
0_0_32425285_17920.cpp:39:29: error: 'memset' was not declared in this scope
     memset(vis,0,sizeof(vis));
                             ^
0_0_32425285_17920.cpp: In function 'void inverse()':
0_0_32425285_17920.cpp:73:32: error: 'memset' was not declared in this scope
     memset(head,-1,sizeof(head));
                                ^
0_0_32425285_17920.cpp: In function 'int maxFlow(int, int)':
0_0_32425285_17920.cpp:102:29: error: 'memset' was not declared in this scope
         memset(a,0,sizeof(a));
                             ^