View Compilation Error

0_0_27782864_9805.cpp:4:13: error: storage size of 'a' isn't known
 int b[13],a[];
             ^
0_0_27782864_9805.cpp:5:9: error: redefinition of 'int b [13]'
 int b[13] ={"rat","ox","tiger","rabbit","dragon","snake","horse","sheep","monkey","rooster","dog","pig"}
         ^
0_0_27782864_9805.cpp:4:5: note: 'int b [13]' previously declared here
 int b[13],a[];
     ^
0_0_27782864_9805.cpp:7:9: error: storage size of 's2' isn't known
 char s2[];
         ^
0_0_27782864_9805.cpp: In function 'int main()':
0_0_27782864_9805.cpp:20:9: error: 's1' was not declared in this scope
    gets(s1);
         ^
0_0_27782864_9805.cpp:25:10: error: 's1' was not declared in this scope
  if(b[n]=s1[]) n=n+1;
          ^
0_0_27782864_9805.cpp:25:13: error: expected primary-expression before ']' token
  if(b[n]=s1[]) n=n+1;
             ^
0_0_27782864_9805.cpp:26:13: error: expected primary-expression before ']' token
  if(b[m]=s2[]) m=m+1;
             ^