View Compilation Error

0_0_31585804_5462.c: In function 'DFS':
0_0_31585804_5462.c:7:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int i = 0;i<6;++i)
   ^
0_0_31585804_5462.c:7:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_31585804_5462.c:15:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i = k;i<n;++i){
  ^
0_0_31585804_5462.c: In function 'main':
0_0_31585804_5462.c:28:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int i = 0;i<n;++i){
   ^