View Compilation Error

0_0_35412751_11587.c: In function 'main':
0_0_35412751_11587.c:17:6: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
      for(int i=1;i<n+1;i++)
      ^
0_0_35412751_11587.c:17:6: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_35412751_11587.c:20:17: error: redefinition of 'i'
         for(int i=0; i<n+1; i++){
                 ^
0_0_35412751_11587.c:17:14: note: previous definition of 'i' was here
      for(int i=1;i<n+1;i++)
              ^
0_0_35412751_11587.c:20:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for(int i=0; i<n+1; i++){
         ^