View Compilation Error

0_0_25126404_14055.c: In function 'main':
0_0_25126404_14055.c:8:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=1;i<=n;i++)
  ^
0_0_25126404_14055.c:8:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_25126404_14055.c:14:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int i_1=0;i_1<m;i_1++)
   ^
0_0_25126404_14055.c:16:11: error: redefinition of 'i_1'
   for(int i_1=0;i_1<m;i_1++)
           ^
0_0_25126404_14055.c:14:11: note: previous definition of 'i_1' was here
   for(int i_1=0;i_1<m;i_1++)
           ^
0_0_25126404_14055.c:16:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int i_1=0;i_1<m;i_1++)
   ^
0_0_25126404_14055.c:19:4: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
    for(int j=i_1;j<m;j++)
    ^