C :

#include<stdio.h>

void main(){
	int i,n,j;
	scanf("%d",&n);
	
	for(i=1;i<=n*1.0/3;i++){
		for(j=i;j<=(n-i)/2;j++){
				printf("%d=%d+%d+%d\n",n,i,j,n-i-j);
		}
	}	
}

C++ :

#include <bits/stdc++.h>
using namespace std;
 
int main(){
    int n,j;
    cin>>n;
    for(int i = 1;i <= n / 3;i++){
    	for(j = i;j <= (n-i)/2;j++){
    		cout<<n<<"="<<i<<"+"<<j<<"+"<<(n-i-j)<<endl;  
		}
    }
}

Java :

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a =sc.nextInt();
		sc.close();
		for(int i=1;i<a;i++) {
			for(int j=1;j<=a;j++) {
				int k=a-i-j;
				if(k>=i&&k>=j&&j>=i) {
					System.out.println(a+"="+i+"+"+j+"+"+k);
				}
			}
		}
	}
}

Python :

# 接收输入,整型
n = int(input())
#注意循环的开始数
for i in range(1, n):
    for j in range(i, n):
        for k in range(j, n):
            if i + j + k == n:
                print('%d=%d+%d+%d' % (n, i, j, k))