public int SubString1(string s)
{
BalanceItem res = new BalanceItem();
List <BalanceItem> intervals = new List <BalanceItem>();
for (int i = 0; i < s.Length; i++)
{
char c = s[i];
char lowerCaseC = char.ToLower(c);
BalanceItem pair = intervals.SingleOrDefault(item => item.LowerCases.Contains(lowerCaseC));
if (pair == null)
{
pair = new BalanceItem(lowerCaseC);
intervals.Add(pair);
}
if (char.IsUpper(c))
{
pair.UpperCasePos = i;
}
else
{
pair.LowerCasePos = i;
}
pair.StartPos = Min(pair.UpperCasePos, pair.LowerCasePos); //Notes: this is fantastic idea
pair.EndPos = Max(pair.UpperCasePos, pair.LowerCasePos);
BalanceItem currentSmallestInterval = FindSmallestInterval(intervals, s);
res = Min(res, currentSmallestInterval);
}
return(res.IsUpperLowerSet()
? res.Distance()
: -1);
}
public int SubString(string s)
{
int[] upper = new int[26];
int[] lower = new int[26];
for (int i = 0; i < 26; i++)
{
upper[i] = BalanceItem.INT_MIN;
lower[i] = BalanceItem.INT_MIN;
}
BalanceItem res = new BalanceItem();
List <BalanceItem> intervals = new List <BalanceItem>();
for (int i = 0; i < s.Length; i++)
{
char c = s[i];
if (char.IsUpper(c))
{
upper[c - 'A'] = i;
}
else
{
lower[c - 'a'] = i;
}
for (int j = 0; j < 26; j++)
{
BalanceItem existedItem = intervals.FirstOrDefault(item => item.LowerCases.Contains(Convert.ToChar('a' + j)));
if (existedItem != null)
{
existedItem.StartPos = Min(upper[j], lower[j]); //Notes: this is fantastic idea
existedItem.EndPos = Max(upper[j], lower[j]);
}
else
{
var item = new BalanceItem(Convert.ToChar('a' + j), Min(upper[j], lower[j]), Max(upper[j], lower[j]));
intervals.Add(item);
}
}
BalanceItem currentSmallestInterval = FindSmallestInterval(intervals, s);
res = Min(res, currentSmallestInterval);
}
return(res.IsUpperLowerSet()
? res.Distance()
: -1);
}
private BalanceItem FindSmallestInterval(List <BalanceItem> m, string s)
{
var orderedItems = m.OrderBy(balanceItem => balanceItem.StartPos).ToList();
List <BalanceItem> merged = new List <BalanceItem>();
var result = new BalanceItem();
for (int i = 0; i < m.Count; i++)
{
var item = orderedItems[i];
if (item.IsUpperLowerSet())
{
var mergedItem = item.Clone();
if (mergedItem.IsShortedBalance())
{
return(mergedItem);
}
if (merged.Count > 0)
{
BalanceItem lastMerged = merged.Last();
if (mergedItem.StartPos < lastMerged.EndPos && lastMerged.EndPos < mergedItem.EndPos)
{
lastMerged.EndPos = mergedItem.EndPos;
lastMerged.AddLowerCase(mergedItem.LowerCases);
if (lastMerged.IsBalance(s) && lastMerged.Distance() < result.Distance())
// if (lastMerged.Distance() < result.Distance())
{
result = lastMerged;
}
continue;
}
}
merged.Add(mergedItem);
}
}
return(result);
}
private BalanceItem Min(BalanceItem item1, BalanceItem item2)
{
return(item1.Distance() <= item2.Distance() ? item1 : item2);
}