Java求阶乘的和
来源:百度知道 编辑:UC知道 时间:2024/06/08 17:28:57
public static void main(String args[]){
long a,u,b;
u=1;
b=0;
for(a=1;a<=20;a++){
u=u*a;
b=b+u;
System.out.println(a+"!="+ b );
}
}}
要求是输出1!=1
1!+2!=3
1!+2!+3!=9
•
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但是我无法让其输出这种形式,高手帮我修改一下,谢谢了!
测试已经通过
public class Test1 {
public static void main(String args[]) {
long a, u, b;
u = 1;
b = 0;
String str = null;
for (a = 1; a <= 20; a++) {
u = u * a;
b = b + u;
if (a == 1) {
str = a + "!";
} else {
str = str + "+" + a + "!";
}
System.out.println(str + "=" + b);
}
}
}
结果
1!=1
1!+2!=3
1!+2!+3!=9
1!+2!+3!+4!=33
1!+2!+3!+4!+5!=153
1!+2!+3!+4!+5!+6!=873
1!+2!+3!+4!+5!+6!+7!=5913
1!+2!+3!+4!+5!+6!+7!+8!=46233
1!+2!+3!+4!+5!+6!+7!+8!+9!=409113
1!+2!+3!+4!+5!+6!+7!+8!+9!+10!=4037913
1!+2!+3!+4!+5!+6!+7!+8!+9!+10!+11!=43954713
1!+2!+3!+4!+5!+6!+7!+8!+9!+10!+11!+12!=522956313
1!+2!+3!+4!+5!+6!+7!+8!+9!+10!+11!+12!+13!=6749977113
1!+2!+3!+4!+5!+6!+7!+8!+9!+10!+11!+12!+13!+14!=93928268313