189. Rotate Array

Topic:

Rotate an array of n elements to the right by K steps.

For example, with n = 7 and k = 3, the array is [1,2,3,4,5,6,7] rotated to [5,6,7,1,2,3,4] .

Note:
Try to come up as many solutions as can, there is at least 3 different ways to solve this problem.

Answer:

Loop right shift of the array:

Three flips, time complexity O (n) without opening up additional space

1 classSolution {2  Public:3     voidRotate (vector<int>& Nums,intk) {4         intI,temp,n;5n=nums.size ();6         if(n==0){7             return;8         }9         Else{Tenk=k%N; One          for(i=0;i< (N-K)/2; i++){ Atemp=Nums[i]; -nums[i]=nums[n-k-1-i]; -nums[n-k-1-i]=temp; the         } -          for(i=n-k;i< (n2-K)/2; i++){ -temp=Nums[i]; -nums[i]=nums[n*2-k-1-i]; +nums[n*2-k-1-i]=temp; -         } +          for(i=0; i<n/2; i++){ Atemp=Nums[i]; atnums[i]=nums[n-1-i]; -nums[n-1-i]=temp; -         } -       }  -     } -};

Note the use of sizeof () and size ():

Size () is a function of the size (length) defined in a class, such as String A; A.size () asks for the size of a.
sizeof () is a standard identifier defined in the C language that is used to calculate the spatial size of a variable, such as String a;sizeof (a), which is the size of the memory space occupied by a.

189. Rotate Array