foo.c: In function 'FindSecondMax':
foo.c:24:26: error: 'max' undeclared (first use in this function); did you mean 'max2'?
   24 |                 if (a[i]>max)
      |                          ^~~
      |                          max2
foo.c:24:26: note: each undeclared identifier is reported only once for each function it appears in
foo.c:31:35: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   31 |                 else if(a[i]==max1&&max1!=max2||a[i]>max2)
      |                         ~~~~~~~~~~^~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务