View Compilation Error

221009_0_24213.c: In function `main':
221009_0_24213.c:19: error: 'for' loop initial declaration used outside C99 mode
221009_0_24213.c:40: error: `true' undeclared (first use in this function)
221009_0_24213.c:40: error: (Each undeclared identifier is reported only once
221009_0_24213.c:40: error: for each function it appears in.)