View Compilation Error

0_0_37470395_10319.c: In function 'greedy':
0_0_37470395_10319.c:7:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int k = 0; k < n; k++){
   ^
0_0_37470395_10319.c:7:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_37470395_10319.c:22:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int j = 0; j < n; j++){
     ^
0_0_37470395_10319.c: In function 'main':
0_0_37470395_10319.c:33:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (int test_number = 1; test_number <= test_cases; test_number++){
   ^