Returns the subscript of a specified key in a circular ordered array.

RT

A circular ordered array refers to the following Array

10 11 12 13 14 1 2 3 4 5 6 7 8 9

For ease of use, array elements are not the same.

Solution:

We can first divide it into two parts to determine whether the order on the left is correct.

If the order is on the left, determine whether the key is on the left.

If the left side is not ordered, it also determines whether the key is on the left.

If none of the above statements are true

The key may be on the right.

/*************************************** **************************************** # Author: neo Fung # Email: neosfung@gmail.com # Last modified: # filename: binsearch. CPP # description: **************************************** **************************************/# ifdef _ msc_ver # define debug # DEFINE _ crt_secure_no_deprecate # endif # include <fstream> # include <stdio. h> # include <Iost Ream> # include <string. h> # include <string> # include <limits. h> # include <algorithm> # include <math. h> # include <numeric> # include <functional> # include <ctype. h> using namespace STD; const int Kmax = 10010; const double Keps = 10e-6; int num [Kmax]; int binsearch (const int * array, const Int & N, const Int & Key) {int L = 0, r = n-1, t =-1; while (L <= r) {int mid = L + (R-l)> 1 ); if (array [l] <= array [Mid] & array [l] <= Key & Key <= array [Mid] | array [l]> array [Mid] & (array [l] <= Key | key <= array [Mid]) {T = mid; R = mid-1;} elsel = Mid + 1;} If (t =-1) return t; else return (array [T] = Key )? T:-1;} int main (void) {# ifdef debug freopen (".. /stdin.txt "," r ", stdin); freopen (".. /stdout.txt "," W ", stdout); # endif int N, key; CIN> N; For (INT I = 0; I <n; ++ I) cin> num [I]; CIN> key; printf ("% d \ n", binsearch (Num, N, key); Return 0 ;}

Input example:

14
10 11 12 13 14 1 2 3 4 5 6 7 8 9
5