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CodePudding user response:

First, single cycle n times, O (n),
Second question, the outer loop n times, the inside of the loop to the outer variable values, similar to the triangular matrix traversal, needs n * n/2 operation, time complexity O (n),
Question 3, recursive calls n, O (n),

CodePudding user response:

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Fact (n) {
If (n=1) or (n=0) return 1
Else if (n % 2=0) return fact fact (n - 1) + (n - 2)
The else return (fact fact (n - 1) + (n - 2)) * 2
}
The time complexity (don't do the cache), take the T (n)=T (n - 1) + T (n - 2), the equivalent of a Fibonacci series, according to its general term formula, its time complexity is O (((1 + SQRT (5))/2) ^ n]