regex matches with intersection in C#

I wonder if it is possible to get MatchCollection with all matches even if there's intersection among them.

string input = "a a a";
Regex regex = new Regex("a a");
MatchCollection matches = regex.Matches(input);
Console.WriteLine(matches.Count);

This code returns 1, but I want it to return 2. How to achive it开发者_JAVA百科?

Thank you for your help.

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string input = "a a a";
Regex regexObj = new Regex("a a");
Match matchObj = regexObj.Match(input);
while (matchObj.Success) {
    matchObj = regexObj.Match(input, matchObj.Index + 1); 
}

will iterate over the string starting the next iteration one character after the position of the previous match, therefore finding all matches.

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You can do it in a while loop by replacing "a a" by "a" and match it another time against the regex until there is no match.