如何用 JavaScript 编写九九乘法表,并显示到页面上?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
var print = function (){
for (var i = 1; i <= 9; i++) {
var s = "";
for (var j = 1; j <= i; j++) {
s += i+"*"+j+"="+(i*j)+" ";
};
s += "</br>";
document.write(s);
};
}
print();
</script>
</body>
</html>
有 1、2、3、4 个数字,能组成多少个互不相同且无重复数字的三位数?都是多少?
import java.util.ArrayList;
import java.util.List;
public class Zuoye {
public static List<Integer> a = new ArrayList<>();
public static void put () {
for (int i = 1; i <= 4; i++) {
for(int j = 1; j <= 4; j++) {
if (i ==j) {
continue;
}
for(int r = 1; r <= 4; r++) {
if(i == r || j == r) {
continue;
}
a.add(i*100+j*10+r);
}
}
}
}
public static void main(String[] args) {
put();
System.out.println(a.size());
for (Integer b : a ) {
System.out.println(b);
}
}
}