剑指offer 11,12

剑指offer 11,12

1.旋转数组的最小数字

 方法1：

    public static int method2(int[] numbers){
        if(numbers.length == 1) return numbers[0];
        else{
            int firstNum,secondNum ,min = numbers[0];
            for(int i = 0; i < numbers.length - 1; i++) {
                firstNum = numbers[i];
                secondNum = numbers[i+1];
                if(firstNum>secondNum) return secondNum;

            }
            return min;
        }
    }

2.矩阵中的路径

方法1：

class Solution {


    public boolean exist(char[][] board,String word){
        
        for (int i = 0; i < board.length; i++) {
            for (int j = 0; j < board[0].length; j++) {
                if(board[i][j] == word.charAt(0)){
                    int[][] indexState = new int[board.length][board[0].length];
                    int wordIndex = 0;
                    indexState[i][j] = 1;
                    wordIndex ++;
                    int x = i,y=j;
                    // 从第一个符合word单词第一个字的位置向周边搜索
                    while(true){
                        if(wordIndex == word.length()) return true;
                        else if(isRight(board,indexState,x-1,y,word.charAt(wordIndex))) x--;
                        else if(isRight(board,indexState,x,y-1,word.charAt(wordIndex))) y--;
                        else if(isRight(board,indexState,x+1,y,word.charAt(wordIndex))) x++;
                        else if(isRight(board,indexState,x,y+1,word.charAt(wordIndex))) y++;
                        else break;
                        wordIndex++;
                    }

                }
            }
        }

        return false;
    }

    public static boolean isRight(char[][] board,int[][] indexState,int x,int y,char target){
        if(x>=0 && x <board.length && y >=0 && y < board[0].length && indexState[x][y] != 1 && board[x][y] == target)
            return true;
        return false;
    }
}