-
Notifications
You must be signed in to change notification settings - Fork 3
/
2272.cpp
51 lines (44 loc) · 1.79 KB
/
2272.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
class Solution {
public:
int largestVariance(string s) {
int n = s.size();
int res = 0;
// choose two char for compare
// p is the one with higher freq.
// q is the one with lower freq.
for (char p = 'a'; p <= 'z'; p++) {
for (char q = 'a'; q <= 'z'; q++) {
if (p == q) continue;
// run Kadane's algo
int pCount = 0; // higher one
int qCount = 0; // lower one
// this flag would deal with the edge case
// e.g., "pqpppppp"
// after reset, there is no q but we can extend
// the interval to the previous q
// and the answer should -1
bool canExtendprevQ = false;
for (auto c : s) {
if (c == p) pCount++;
if (c == q) qCount++;
// an interval should contain at least one q
if (qCount > 0) {
res = max(res, pCount - qCount);
}
// edge case: consider previous q
else if (qCount == 0 && canExtendprevQ) {
res = max(res, pCount - qCount - 1);
}
// reset if # of q > # of p
if (qCount > pCount) {
qCount = pCount = 0;
// once reset, the interval can be extended
// as there must be one q before the next interval
canExtendprevQ = true;
}
}
}
}
return res;
}
};