foo.c: In function 'main':
foo.c:11:16: error: 'max' undeclared (first use in this function); did you mean 'main'?
    printf("%d",max);
                ^~~
                main
foo.c:11:16: note: each undeclared identifier is reported only once for each function it appears in
foo.c: In function 'zuidazhi':
foo.c:31:29: warning: passing argument 1 of 'zuidazhi' makes pointer from integer without a cast [-Wint-conversion]
        max=(a[n-1]>zuidazhi(n-1)?a[n-1]:zuidazhi(n-1));
                             ^
foo.c:22:5: note: expected 'int *' but argument is of type 'int'
 int zuidazhi(int a[],int n)
     ^~~~~~~~
foo.c:31:20: error: too few arguments to function 'zuidazhi'
        max=(a[n-1]>zuidazhi(n-1)?a[n-1]:zuidazhi(n-1));
                    ^~~~~~~~
foo.c:22:5: note: declared here
 int zuidazhi(int a[],int n)
     ^~~~~~~~
foo.c:31:50: warning: passing argument 1 of 'zuidazhi' makes pointer from integer without a cast [-Wint-conversion]
        max=(a[n-1]>zuidazhi(n-1)?a[n-1]:zuidazhi(n-1));
                                                  ^
foo.c:22:5: note: expected 'int *' but argument is of type 'int'
 int zuidazhi(int a[],int n)
     ^~~~~~~~
foo.c:31:41: error: too few arguments to function 'zuidazhi'
        max=(a[n-1]>zuidazhi(n-1)?a[n-1]:zuidazhi(n-1));
                                         ^~~~~~~~
foo.c:22:5: note: declared here
 int zuidazhi(int a[],int n)
     ^~~~~~~~
foo.c: In function 'main':
foo.c:6:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&n);
    ^~~~~~~~~~~~~~
foo.c: In function 'shuru':
foo.c:19:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&a[i]);
         ^~~~~~~~~~~~~~~~~

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