View Compilation Error

0_0_18175024_2246.c: In function 'getans':
0_0_18175024_2246.c:38:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int i=0;i<30;i++)
     ^
0_0_18175024_2246.c:38:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_18175024_2246.c:40:13: error: redefinition of 'i'
     for(int i=0;i<d;i++){
             ^
0_0_18175024_2246.c:38:13: note: previous definition of 'i' was here
     for(int i=0;i<30;i++)
             ^
0_0_18175024_2246.c:40:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int i=0;i<d;i++){
     ^
0_0_18175024_2246.c: In function 'main':
0_0_18175024_2246.c:50:5: error: expected expression before '/' token
     //freopen("in","r",stdin);
     ^