/in/foo.cc: In function 'int main()':
/in/foo.cc:42:13: warning: suggest parentheses around comparison in operand of '==' [-Wparentheses]
  cost[i][j] == i==j ? 0 : INF;
  ~~~~~~~~~~~^~~~
/in/foo.cc:42:30: warning: second operand of conditional expression has no effect [-Wunused-value]
  cost[i][j] == i==j ? 0 : INF;
                              ^
/in/foo.cc:42:30: warning: third operand of conditional expression has no effect [-Wunused-value]