if you compile in C change
for (int i=0;i<10;i++) { ..
to
int i;
for (i=0;i<10;i++) { ..
You can also compile with the C99 switch set. Put -std=c99 in the compilation line:
gcc -std=c99 foo.c -o foo
REF: http://cplusplus.syntaxerrors.info/index.php?title='for'_loop_initial_declaration_used_outside_C99_mode