I was looking submission of other user and i noticed something common in them,↵
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#ifdef ONLINE_JUDGE↵
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#define OJ \↵
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freopen(file".in", "r", stdin); \↵
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freopen(file".out", "w", stdout);↵
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#else↵
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#define OJ ;↵
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#endif↵
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I want to know how this works .Please help.↵
And how to use it and what does it do?↵
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#ifdef ONLINE_JUDGE↵
↵
#define OJ \↵
↵
freopen(file".in", "r", stdin); \↵
↵
freopen(file".out", "w", stdout);↵
↵
#else↵
↵
#define OJ ;↵
↵
#endif↵
↵
I want to know how this works .Please help.↵
And how to use it and what does it do?↵