Search a 2D Matrix II

http://www.lintcode.com/en/problem/search-a-2d-matrix-ii/

Solution

class Solution {
public:
    /**
     * @param matrix: A list of lists of integers
     * @param target: An integer you want to search in matrix
     * @return: An integer indicate the total occurrence of target in the given matrix
     */
    int searchMatrix(vector<vector<int> > &matrix, int target) {
        int m = matrix.size();
        if(m == 0) return 0;
        int n = matrix[0].size();
        if(n == 0) return 0;
        int i = 0, j = n-1;
        int cnt = 0;
        while(i<m && j<n) {
            if(matrix[i][j] == target) {
                cnt++;
                i++;
                j--;
            } else if(matrix[i][j] > target) {
                j--;
            } else {
                i++;
            }
        }
        return cnt;
    }
};