201301 JAVA 题目2-3级

DP

import java.util.*;

public class Main {

    public Main() {
    }

    public int count(int n, int m) {
        int[][] dp = new int [n][m];
        for (int i = 0; i < n; i++) {
            dp[i][0] = 1;
        }
        for (int j = 0; j < m; j++) {
            dp[0][j] = 1;
        }
        for (int i = 1; i < n; i++) {
            for (int j = 1; j < m; j++) {
                dp[i][j] = dp[i-1][j] + dp[i][j-1];
            }
        }
        return dp[n-1][m-1];
    }

    public static void main(String[] args) {
        Main solution = new Main();
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int n = in.nextInt() + 1;
            int m = in.nextInt() + 1;
            int res = solution.count(n, m);
            System.out.println(res);
        }
    } 
}