C :

#include <stdio.h>

int f(int n, int m) {
	if (n < 1 || m < 1)
		return 0;
	else if (n == 1 || m == 1)
		return 1;
	else if (n < m)
		return f(n, n);
	else if (n == m)
		return f(n, n - 1) + 1;
	else
		return f(n, m - 1) + f(n - m, m);
}

int main() {
	int n;
	scanf("%d", &n);
	if (n >= 2 && n <= 10) {
		int r = f(n, n);
		printf("%d\n", r);
	} else {
		printf("输入不合法，请输入 2 到 10 之间的正整数。\n");
	}
	return 0;
}

C++ :

#include <bits/stdc++.h>
using namespace std;
#define int long long
int ans = 0;
int n;
vector<string>op;

void dfs(int x, int st, string s) {
	if (st > n)
		return;
	if (st == n) {
		op.push_back(s);
//		cout << s << endl;
		ans++;
		return;
	}
	for (int i = 1; i <= x; i++) {
		char c = i + '0';
		string ks;
		ks += c;
		ks += '+';
		ks += s;
		dfs(i, st + i, ks);
	}
}

signed main() {
//	freopen("C:\\Users\\lenovo\\Desktop\\计算机\\尝试-大二\\算法基础\\2\\3.in", "r", stdin);
//	freopen("C:\\Users\\lenovo\\Desktop\\计算机\\尝试-大二\\算法基础\\2\\3.out", "w", stdout);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		string s;
		s += i + '0';
		dfs(i, i, s);
	}
//	sort(op.begin(), op.end());
//	for (string lp : op) {
//		if (lp.size() == 1)
//			break;
//		cout << lp << endl;
//	}
	cout << ans;
	return 0;
}

Java :

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        Bs bs = new Bs();
        System.out.println(bs.center(n,n));
    }

    public static class Bs {
        public int center(int n, int m) {
            if (n == 1 || m == 1) {
                return 1;
            } else if (n < m) {
                return center(n, n);
            } else if (n == m) {
                return center(n, m - 1) + 1;
            } else {
                return center(n, m - 1) + center(n- m, m);
            }
        }
    }
}