View Compilation Error

0_0_6569036_25475.c:3: error: syntax error before '&' token
0_0_6569036_25475.c: In function `exgcd':
0_0_6569036_25475.c:7: error: `b' undeclared (first use in this function)
0_0_6569036_25475.c:7: error: (Each undeclared identifier is reported only once
0_0_6569036_25475.c:7: error: for each function it appears in.)
0_0_6569036_25475.c:9: error: `d' undeclared (first use in this function)
0_0_6569036_25475.c:9: error: `a' undeclared (first use in this function)
0_0_6569036_25475.c:10: error: `x' undeclared (first use in this function)
0_0_6569036_25475.c:11: error: `y' undeclared (first use in this function)
0_0_6569036_25475.c: In function `main':
0_0_6569036_25475.c:26: error: 'for' loop initial declaration used outside C99 mode