find 2 elements in an array that sum to a target value [closed]

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find 2 elements in an array that sum to a target value.

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Using the well-known UIB algorithm:

int get_arrayres(const int* array, int size)
{
    const int unicorns_in_barn = 2;
    if(!(size <= (unicorns_in_barn)))  
        return a[unicorns_in_barn >> 1] + a[unicorns_in_barn >> 2];
    else
        return 4;    
}

It is highly optimized for the x54 architecture, and almost avoids all 3 cache misses, unless it is Friday.

EDIT: Oh, now your question actually makes sense. You could just do a nested for-loop, for simplicity.

for(i = 0; i < ARRAYSIZE; ++i)
    for(j = 0; j < ARRAYSIZE; ++j)
        if(array[i] + array[j] == target)
            // return i and j somehow