View Compilation Error

0_0_4122384_29416.cpp:4: error: `string' does not name a type
0_0_4122384_29416.cpp: In function `int main(int, char**)':
0_0_4122384_29416.cpp:53: error: `x1' undeclared (first use this function)
0_0_4122384_29416.cpp:53: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4122384_29416.cpp:53: error: `y1' undeclared (first use this function)
0_0_4122384_29416.cpp:61: error: `x' undeclared (first use this function)
0_0_4122384_29416.cpp:61: error: `y' undeclared (first use this function)