View Compilation Error

0_0_19028217_23386.c: In function 'main':
0_0_19028217_23386.c:41:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for (int i = 1; i <= n; i++) {
         ^
0_0_19028217_23386.c:41:9: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_19028217_23386.c:58:17: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
                 for (int i = l + 2; i <= r + 1; i++) {
                 ^