[C++知识库]搜索二维矩阵(二分法)-C语言

搜索二维矩阵(二分法)

#include <stdio.h>
#include <stdbool.h>

bool searchMatrix(int (*matrix)[4], int matrixrow, int *matrixcol, int target);

int main()
{
	int matrix[][4] = {{1, 3, 5, 7}, {10, 11, 16, 20}, {23, 30, 34, 60}};
	int target = 13;
	int matrixrow = 3;
	int matrixcol = 4;
	bool flag = searchMatrix(matrix, matrixrow, &matrixcol, target);
	if(flag == false)
		printf("false");
	else
		printf("true");
}

bool searchMatrix(int (*matrix)[4], int matrixrow, int *matrixcol, int target)
{
	//验证指针是否为空以及行数
	if(matrix == NULL || matrixrow == 0)
		return false;
    int row = matrixrow;
    int col = *matrixcol;
    int left = 0;
    int right = row * col - 1;
    int mid = 0;
    int elm = 0;
    while(left <= right)
    {
    	mid = (left + right) >> 1;  //除以2
    	//两种方式
//    	elm = matrix[mid / col][mid % col];
		elm = *(*(matrix + mid / col) + mid % col);
    	if(elm == target)
    		return true;
		else if(elm >= target)
			right = mid - 1;
		else
			left = mid + 1;
	}
	return false;
}