/in/foo.c: In function 'FindMaxNeg':
/in/foo.c:7:8: warning: unused variable 'x' [-Wunused-variable]
    int x=0;//设置x为最小正整数
        ^
/in/foo.c: In function 'main':
/in/foo.c:25:14: warning: variable 'maxNegB' set but not used [-Wunused-but-set-variable]
  int maxNegA,maxNegB;
              ^~~~~~~
/in/foo.c:25:6: warning: variable 'maxNegA' set but not used [-Wunused-but-set-variable]
  int maxNegA,maxNegB;
      ^~~~~~~
/in/foo.c: In function 'FindMaxNeg':
/in/foo.c:18:11: warning: 'maxNeg' may be used uninitialized in this function [-Wmaybe-uninitialized]
    return maxNeg;
           ^~~~~~