Java实现1加到100，求解

Question

如题所述

Answer 1

public class Demo{
public static void main(String[] args) {
int result = 0;//定义一个变量用来存结果
for(int i=1;i<=100;i++){
result += i;//从1循环加到100
}
System.out.println(result);
}
}

Answer 2

import java.util.Scanner;

public class Demo{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int a = sc.nextInt();
int sum=0;
do{
sum += a;
a--;
}while(a>0);
System.out.println(sum);
System.out.println("-------------------");

int b =sc.nextInt();
int sum1=0;
for(int i=1;i<=b;i++){
sum1 += i;
}
System.out.println(sum1);
System.out.println("--------------------");

int c =sc.nextInt();
int sum2=0;
while(c>=1){
sum2 +=c;
c--;
}
System.out.println(sum2);
}
}

Answer 3

public class Sum {
 public static void main(String[] args) {
  System.out.println(sum(100));
 }
 public static int sum(int i) {
  if (i == 1) {
   return 1;
  }
  return sum(i - 1) + i;
 }
}