/in/foo.cc: In function 'int read()':
/in/foo.cc:7:31: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   while(ch>'9'||ch<'0')ch=='-'&&(f=0)||(ch=getchar());
                        ~~~~~~~^~~~~~~
/in/foo.cc: In function 'int main(int, const char**)':
/in/foo.cc:37:33: warning: 'pa' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if (pa != cnt && abs(fst[pa + 1] - i) < res) {
                              ~~~^~~