leetcode/range_search.java at master · mapan/leetcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
public class Solution {
    public int[] searchRange(int[] A, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        int[] range=new int[]{-1,-1};
        int lower = 0,n=A.length-1;
        int upper = n;
        int mid;

        // Search for lower bound
        while (lower <= upper) {
            mid = (lower + upper) / 2;
            if (A[mid] < target)
                lower = mid + 1;
            else
                upper = mid-1;
        }

        // If the target is not found, return (-1, -1)
        if (lower==A.length||A[lower] != target)
            return range;
        range[0] = lower;

        // Search for upper bound
        upper = n;
        while (lower <= upper) {
            mid = (lower + upper) / 2;
            if (A[mid] > target)
                upper = mid-1;
            else
                lower = mid + 1;
        }
        range[1] = upper;

        return range;
    }
}


public class Solution {
    public int[] searchRange(int[] A, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        int l=0,r=A.length-1;
        while(l<=r) {
            int mid=l+(r-l)/2;
            if(A[mid]>target) r=mid-1;
            else if(A[mid]<target) l=mid+1;
            else {
                int s=bs(A,l,mid-1,target-0.1);
                int e=bs(A,mid+1,r,target+0.1);
                return new int[]{s,e-1};
            }
        }
        return new int[]{-1,-1};
    }
    public int bs(int[] A,int l,int r,double target) {
        while(l<=r) {
            int mid=l+(r-l)/2;
            if(A[mid]>target) r=mid-1;
            else if(A[mid]<target) l=mid+1;
            //else return mid;
        }
        return l;
    }
}

class Solution {
public:
    vector<int> searchRange(int A[], int n, int target) {
        vector<int> range(2, -1);
        int lower = 0;
        int upper = n;
        int mid;

        // Search for lower bound
        while (lower < upper) {
            mid = (lower + upper) / 2;
            if (A[mid] < target)
                lower = mid + 1;
            else
                upper = mid;
        }

        // If the target is not found, return (-1, -1)
        if (A[lower] != target)
            return range;
        range[0] = lower;

        // Search for upper bound
        upper = n;
        while (lower < upper) {
            mid = (lower + upper) / 2;
            if (A[mid] > target)
                upper = mid;
            else
                lower = mid + 1;
        }
        range[1] = upper - 1;

        return range;
    }
};