/in/foo.cc: In function 'int main()':
/in/foo.cc:30:5: warning: comparison of constant '1000' with boolean expression is always true [-Wbool-compare]
 1<=a<=1000;
 ~~~~^~~~~~
/in/foo.cc:30:2: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
 1<=a<=1000;
 ~^~~
/in/foo.cc:30:5: warning: statement has no effect [-Wunused-value]
 1<=a<=1000;
 ~~~~^~~~~~
/in/foo.cc:31:5: warning: comparison of constant '1000' with boolean expression is always true [-Wbool-compare]
 1<=b<=1000;
 ~~~~^~~~~~
/in/foo.cc:31:2: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
 1<=b<=1000;
 ~^~~
/in/foo.cc:31:5: warning: statement has no effect [-Wunused-value]
 1<=b<=1000;
 ~~~~^~~~~~
/in/foo.cc:28:13: warning: unused variable 'x' [-Wunused-variable]
 int a,b,c,d,x,y;
             ^
/in/foo.cc:28:15: warning: unused variable 'y' [-Wunused-variable]
 int a,b,c,d,x,y;
               ^
/in/foo.cc: In function 'int zuixiaogongbeishu(int, int)':
/in/foo.cc:11:3: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
  k=l*i/k;
  ~^~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:11:3: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
  k=l*i/k;
  ~^~~~~~
/in/foo.cc:5:6: note: 'k' was declared here
  int k,l=m,i=n;
      ^