math - How can I simply check if a set of n numbers are all different? -

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i have n integers , need quick logic test see different, , don't want compare every combination find match...any ideas on nice , elegant approach?

i don't care programming language idea in, can convert!

you don't have check every combination commutivity , transitivity; can go down list , check each entry against each entry comes after it. example:

bool areelementsunique( int[] arr ) {     for( int i=0; i<arr.length-1; i++ ) {         for( int j=i+1; j<arr.length; j++ ) {             if( arr[i] == arr[j] ) return false;         }     }     return true; }

note inner loop doesn't start beginning, next element (i+1).


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