View Compilation Error

0_0_20524038_25376.c: In function 'main':
0_0_20524038_25376.c:14:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for(int t = 0; t < T; t++)
         ^
0_0_20524038_25376.c:14:9: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_20524038_25376.c:20:17: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
                 for(int n = 0; n < length; ++n)
                 ^
0_0_20524038_25376.c:38:25: error: redefinition of 'n'
                 for(int n = 0; n < length; ++n)
                         ^
0_0_20524038_25376.c:20:25: note: previous definition of 'n' was here
                 for(int n = 0; n < length; ++n)
                         ^
0_0_20524038_25376.c:38:17: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
                 for(int n = 0; n < length; ++n)
                 ^