74. 搜索二维矩阵 LeetCode 力扣

74. 搜索二维矩阵

二维二分搜索法(代码实现的过于复杂了,改日优化一下)

此题对于二分法模板的提炼是不错的

public boolean searchMatrix(int[][] matrix, int target) {
        if (matrix.length == 0 || matrix[0].length == 0) {
            return false;
        }
        if (matrix.length == 1) {
            if (matrix[0].length == 1) {
                return matrix[0][0] == target;
            }
            return isHaveTarget(matrix, target, 0);
        }
        if (target < matrix[0][0] || target > matrix[matrix.length - 1][matrix[0].length - 1]) {
            return false;
        }
        if (target == matrix[matrix.length - 1][0]) {
            return true;
        } else if (target > matrix[matrix.length - 1][0]) {
            return isHaveTarget(matrix, target, matrix.length - 1);
        } else {
            int targetRowIndex;
            int lowRowIndex = 0;
            int highRowIndex = matrix.length - 1;
            int midRowIndex=0;
            while (lowRowIndex < highRowIndex) {
                midRowIndex = lowRowIndex + (highRowIndex - lowRowIndex) / 2;
                if (matrix[midRowIndex][0] == target) {
                    return true;
                }
                if (matrix[midRowIndex][0] > target) {
                    highRowIndex = midRowIndex - 1;
                }
                if (matrix[midRowIndex][0] < target) {
                    lowRowIndex = midRowIndex + 1;
                }
            }
            if (matrix[midRowIndex][0] > target && matrix[midRowIndex - 1][0] == target) {
                return true;
            }
            if (matrix[midRowIndex][0] < target && matrix[midRowIndex + 1][0] == target) {
                return true;
            }
            if (matrix[lowRowIndex][0] < target) {
                targetRowIndex = lowRowIndex;
            } else {
                targetRowIndex = lowRowIndex - 1;
            }
            return isHaveTarget(matrix, target, targetRowIndex);
        }
    }

    private boolean isHaveTarget(int[][] matrix, int taget, int targetRowIndex) {
        if (taget < matrix[targetRowIndex][0] || taget > matrix[targetRowIndex][matrix[targetRowIndex].length - 1]){
            return false;
        }
        int low = 0;
        int high = matrix[targetRowIndex].length - 1;
        int mid = 0;
        while (low < high) {
            mid = low + (high - low) / 2;
            if (taget == matrix[targetRowIndex][mid]) {
                return true;
            }
            if (taget > matrix[targetRowIndex][mid]) {
                low = mid + 1;
            }
            if (taget < matrix[targetRowIndex][mid]) {
                high = mid - 1;
            }
        }
        if (taget > matrix[targetRowIndex][mid]) {
            return matrix[targetRowIndex][mid + 1] == taget;
        } else {
            return matrix[targetRowIndex][mid - 1] == taget;
        }
    }

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转载自blog.csdn.net/ZhaoXia_hit/article/details/106308481
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