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机器人到达指定位置方法数

import java.util.Scanner;public class Robot {public static int ways(int N,int P,int cur,int rest) {if(rest==0) {return cur==P?1:0;}if(cur==1)return ways(N,P,cur+1,rest-1);if(cur==N)return ways(N,P,cur-1,rest-1);return ways(N,P,cur-1,rest-1)+ways(N,P,cur+1,rest-1);}public static int getAns(int N,int P,int M,int K) {if(M<1||M>N)return 0;return ways(N,P,M,K);}public static int waysDP(int N,int P,int M,int K) {//cur: 1~N  rest: 0~Kint[][] dp=new int[N+1][K+1];dp[P][0]=1;for(int col=1;col<=K;++col) {dp[1][col]=dp[2][col-1];for(int row=2;row<N;++row) {dp[row][col]=(dp[row-1][col-1]+dp[row+1][col-1])%(1000000007);}dp[N][col]=dp[N-1][col-1];}return dp[M][K]%(1000000007);}public static int Ans(int N,int P,int M,int K) {if(M<1||M>N)return 0;return waysDP(N,P,M,K);}public static void main(String[] args) {Scanner scan=new Scanner(System.in);int N,M,K,P;N=scan.nextInt();M=scan.nextInt();K=scan.nextInt();P=scan.nextInt();
//		System.out.println(getAns(N,P,M,K));System.out.println(Ans(N,P,M,K));}}