题解 | #矩阵元素查找#

class Solution {
public:
    int find(vector<int> a, int x) {
        int l = 0, r = a.size() - 1;
        while(l < r) {
            int mid = (l + r) / 2;
            if(x > a[mid])
                l = mid + 1;
            else
                r = mid;
        }
        if(a[l] == x)
            return l;
        else
            return -1;
    }
    vector<int> findElement(vector<vector<int> > mat, int n, int m, int x) {
        // write code here
        vector<int> res;
        for(int i = 0; i < n; i++) {
            int left = mat[i][0], right = mat[i][m-1];
            if(left <= x && x <= right) {
                int l = i;
                int r = find(mat[i], x);
                if(r != -1) {
                    res.push_back(l);
                    res.push_back(r);
                    return res;
                }
            }
            if(x < left)
                break;
        }
        return res;
    }
};