/in/foo.cc: In function 'int build(int, int)':
/in/foo.cc:61:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid=le+ri>>1;
             ~~^~~
/in/foo.cc: In function 'void zig(int)':
/in/foo.cc:86:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
     if (f2)
        ^
/in/foo.cc: In function 'void zag(int)':
/in/foo.cc:96:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
     if (f2)
        ^
/in/foo.cc: In function 'void splay(int)':
/in/foo.cc:119:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
     if (f1)
        ^