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Find the maximum of a vector of 1-byte ints without using multicore, vector instructions, loop unrolling, etc.
Can you do it faster in C than the following?
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max=*x++; for(i=1;i<n;++i){if(max<*x)max=*x; ++x;} |
Hint: |
x←?1e6⍴1000
a. ¯1+{≢⍵}⌸(⍳1000),x 1.00 (_1+#/.~(i.1000),x )
b. ¯1+{≢⍵}⌸(⍳1+⌈/x),x 1.62 (_1+#/.~(i.1+>./x),x)
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| That is, # occurrences of unique elements of x takes 1.00 ;
maximum of x takes 0.62 |
A solution to the puzzle is faster by a factor of 1.5 |
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