//合并array
function hebing_array(a,b) {
for (var i = 0, j = 0, ci, r = {}, c = []; ci = a[i++] || b[j++]; ) {
if (r[ci]) continue;
r[ci] = 1;
c.push(ci);
}
return c;
}
//求差集
function chaji_array(arr1,arr2){
var arr3 = [];
for (var i = 0; i < arr1.length; i++) {
var flag = true;
for (var j = 0; j < arr2.length; j++) {
if (arr2[j] == arr1[i]) {
flag = false;
}
}
if (flag) {
arr3.push(arr1[i]);
}
}
return arr3;
}