View Compilation Error

0_0_7457766_30870.c: In function `main':
0_0_7457766_30870.c:4: error: conflicting types for 'a'
0_0_7457766_30870.c:4: error: previous declaration of 'a' was here
0_0_7457766_30870.c:11: error: invalid initializer
0_0_7457766_30870.c:20: error: `i' undeclared (first use in this function)
0_0_7457766_30870.c:20: error: (Each undeclared identifier is reported only once
0_0_7457766_30870.c:20: error: for each function it appears in.)