fgnjuf's blog

I need help!!!
By fgnjuf, 9 years ago, In English

I have a question that : cin/cout with ios_base::sync_with_stdio(0) and scanf/printf. Which is faster? Can anybody help me? Thank you a lot!

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9 years ago, # |
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look at this

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9 years ago, # |
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or at this

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9 years ago, # |
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Why don't you try to read 5*10^6 or 10^7 integers and see the difference?

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9 years ago, # |
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cin/cout uses operator <<. That is function. If you do cin >> a >> b >> c; you call 3 functions. scanf, printf should be faster still. cin/cout are comfortable and simple, but not flexible as scanf/printf. If you want to find a way to get rid of scanf/printf then it is bad idea. I always recommend to use scanf/printf. There is no thing that scanf/printf can't but cin/cout can.

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    9 years ago, # ^ |
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    There is no thing that scanf/printf can't but cin/cout can.

    To read string for example?

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      9 years ago, # ^ |
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      std::string seems like is using vector like container. This trick does it. But I am not talking about that. I am talking about reading 14 and 32 from "14:32" by ignoring ':', reading string(including spaces and newlines) until ';' or '$'. I do not think that cin can to that easily.

      #include <iostream>
#include <queue>
#include <string>
using namespace std;

string s;

int main(){
	s.resize(1000);
	scanf("%s", &s[0]);
	printf("%d\n", s.size());
	s.resize(strlen(s.c_str()));
	cout << s << endl;
	printf("%s\n%d\n", s.c_str(), s.size());
	return 0;
}
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