hwangganzi's blog

How do you use lower_bound on paired set?
By hwangganzi, history, 5 years ago, In English

I want to find a pair that both first and the second value are bigger than s.lower_bound({a,b})

for example ~~~~ set<pair<int,int>> s; s.insert({50, 40}); s.insert({100, 20}); s.insert({120, 80}); auto it = s.lower_bound({80 , 60 }); ~~~~ if I do like this, iterator will find pair({100,20}). But What I want is pair ({120, 80}) because both first and the second value are bigger than ({80, 60}). for ({100, 20}) the first value is bigger than 80 but the second value is smaller than 60. This is not what I want. Sorry for my bad english, Thank you in advance.

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5 years ago, # |
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a set can't do that because the order you describe is not a total order.

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    5 years ago, # ^ |
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    I think using lower_bound at max 2 times will work .
    You can see my comment below and tell me if I am wrong .

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5 years ago, # |
← Rev. 4   Vote: I like it +15 Vote: I do not like it

Edit : I was wrong .

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