View Compilation Error

0_0_12155869_17708.cpp: In function `int main()':
0_0_12155869_17708.cpp:20: error: `memset' undeclared (first use this function)
0_0_12155869_17708.cpp:20: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12155869_17708.cpp:22: error: `sf' undeclared (first use this function)