/**有需要自取，必须标明出处

  • @param i Number, j Number, a Number, c Number
  • @return Boolean

*/
var Solution = function(i, j, a, c){

var dj=a+c*(j-1)
var di=a+c*(i-2)
var q=(j*(a+dj))/2
var w=((i-1)*(a+di))/2
var z=q-w
return z

};