-
Notifications
You must be signed in to change notification settings - Fork 2
/
fourSum.cpp
55 lines (46 loc) · 1.7 KB
/
fourSum.cpp
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
class Solution {
public:
vector<vector<int> > fourSum(vector<int> &num, int target) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<vector<int> > v;
int a, b, c, d;
if (num.size() < 4)
return v;
sort(num.begin(), num.end());
for (int i = 0; i < num.size() - 3; i++) {
for (int j = i + 1; j < num.size() - 2; j++) {
int k = j + 1;
int l = num.size() - 1;
a = num[i];
b = num[j];
while (k < l) {
c = num[k];
d = num[l];
int sum = a + b + c + d;
if (sum == target) {
addit(v, a, b, c, d);
while (num[k] == c && k < l)
k++;
while (num[l] == d && k < l)
l--;
} else if (sum < target) {
k++;
} else {
l--;
}
}
while (num[j+1] == b && j < num.size() - 2)
j++;
}
while (num[i+1] == a && i < num.size() - 3)
i++;
}
return v;
}
void addit(vector<vector<int> > &v, int a, int b, int c, int d)
{
int tmp[] = {a, b, c, d};
v.push_back(vector<int>(tmp, tmp + 4));
}
};