View Compilation Error

0_0_9777683_12561.cpp: In function `int main()':
0_0_9777683_12561.cpp:5: error: `memset' undeclared (first use this function)
0_0_9777683_12561.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9777683_12561.cpp:19: error: `j' undeclared (first use this function)
0_0_9777683_12561.cpp:21: error: `f' undeclared (first use this function)