题解 | #整数求和#

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n, m;
    cin >> n >> m;
    
    // 创建dp数组并初始化
    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
    
    // 初始化和为0的情况
    for(int i = 0; i <= n; i++) {
        dp[i][0] = 1;
    }
    
    // 动态规划填表
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(j >= i) {
                dp[i][j] = dp[i-1][j-i] + dp[i-1][j];
            } else {
                dp[i][j] = dp[i-1][j];
            }
        }
    }
    
    cout << dp[n][m];
    return 0;
}

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        
        // 创建dp数组并初始化
        int[][] dp = new int[n + 1][m + 1];
        
        // 初始化和为0的情况
        for(int i = 0; i <= n; i++) {
            dp[i][0] = 1;
        }
        
        // 动态规划填表
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                if(j >= i) {
                    dp[i][j] = dp[i-1][j-i] + dp[i-1][j];
                } else {
                    dp[i][j] = dp[i-1][j];
                }
            }
        }
        
        System.out.println(dp[n][m]);
    }
}

def count_combinations(n, m):
    # 创建dp数组并初始化
    dp = [[0] * (m + 1) for _ in range(n + 1)]
    
    # 初始化和为0的情况
    for i in range(n + 1):
        dp[i][0] = 1
    
    # 动态规划填表
    for i in range(1, n + 1):
        for j in range(1, m + 1):
            if j >= i:
                dp[i][j] = dp[i-1][j-i] + dp[i-1][j]
            else:
                dp[i][j] = dp[i-1][j]
    
    return dp[n][m]

n, m = map(int, input().split())
print(count_combinations(n, m))