java 练习递归..找到最大值

Posted 2021-05-08

import java.io.*;
import java.util.*;



class Solution {
  public static void main(String[] args) {
   Solution solution = new Solution();
    int[][] input = {
      {-1,2,41,4,-8},
      {1,3,-9,121,31},
      {1,1,1}
    };
    
    for(int i=0; i< input.length; i++){
       System.out.println("Input :" + Arrays.toString(input[i]) + ", Result:" + solution.findMax(input[i], input[i].length));
      System.out.println("Input :" + Arrays.toString(input[i]) + ", Result:" + solution.findMaxR(input[i],  input[i].length));
      System.out.println("Input :" + Arrays.toString(input[i]) + ", Result:" + solution.findMaxRT(input[i],  input[i].length));
    }
  }
  
  public int findMaxR(int[] input, int size){
    if(input == null || size == 0){
      return Integer.MIN_VALUE;
    }
    int max = findMaxR(input, size-1);
    if(max < input[size-1]){
     max = input[size-1]; 
    }
    return max;  
  }
  
  public int findMaxRT(int[] input, int size){
    if(input == null || size==0){
      return Integer.MIN_VALUE;
    }
    return Math.max(findMaxR(input, size-1), input[size-1]);  
  }
  
  public int findMax(int[] input, int size){
    if(input == null || size < 1){
      return Integer.MIN_VALUE;
    }
    int max = input[0];
    for(int i=0;i<size;i++){
      if(max < input[i]){
        max = input[i]; 
      }
    }
    return max;
  }
}