View Compilation Error

0_0_35886000_27784.c: In function 'copy':
0_0_35886000_27784.c:5:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int cnt=0; main[cnt]!= 0; cnt++)
  ^
0_0_35886000_27784.c:5:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_35886000_27784.c: In function 'refresh':
0_0_35886000_27784.c:15:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int cnt = 1; cnt <= len; cnt++)
  ^
0_0_35886000_27784.c: In function 'display':
0_0_35886000_27784.c:23:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int cnt=0; now[cnt]!= 0; cnt++)
  ^
0_0_35886000_27784.c: In function 'PrintTri':
0_0_35886000_27784.c:37:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int cnt=1; cnt<num; cnt++)
  ^