Rotate Array
Rotate an array of n elements to the right by k steps.
For example, with n = 7 and k = 3,
the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].
1 2 7 4 5 6 3
1 6 7 4 5 2 3
5 6 7 4 1 2 3
Note:
Try to come up as many solutions as you can,
there are at least 3 different ways to solve this problem.
[show hint]
Related problem: Reverse Words in a String II
1 /************************************************************************* 2 > File Name: LeetCode189.c 3 > Author: Juntaran 4 > Mail: Juntaranmail@gmail.com 5 > Created Time: Tue 13 May 2016 16:27:23 PM CST 6 ************************************************************************/ 7 8 /************************************************************************* 9 10 Rotate Array 11 12 Rotate an array of n elements to the right by k steps. 13 14 For example, with n = 7 and k = 3, 15 the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4]. 16 17 1 2 7 4 5 6 3 18 1 6 7 4 5 2 3 19 5 6 7 4 1 2 3 20 21 Note: 22 Try to come up as many solutions as you can, 23 there are at least 3 different ways to solve this problem. 24 25 [show hint] 26 27 Related problem: Reverse Words in a String II 28 29 ************************************************************************/ 30 31 #include <stdio.h> 32 33 void printNums( int* nums, int numsSize ) 34 { 35 int i; 36 for( i=0; i<numsSize; i++ ) 37 { 38 printf("%d ",nums[i]); 39 } 40 printf(" "); 41 } 42 43 void rotate(int* nums, int numsSize, int k) 44 { 45 k = k % numsSize; 46 if(k == 0) 47 { 48 return; 49 } 50 int temp = 0; 51 int left = 0; 52 int right = numsSize-k; 53 int n = numsSize - 1; 54 while( n > 0 ) 55 { 56 if( left == right ) 57 { 58 right ++; 59 left = right + k - numsSize; 60 n --; 61 } 62 63 temp = nums[right]; 64 nums[right] = nums[left]; 65 nums[left] = temp; 66 left = (left + k) % numsSize; 67 68 n --; 69 70 // printNums( nums, numsSize ); 71 } 72 } 73 74 void rotate2(int* nums, int numsSize, int k) 75 { 76 while( k > 0 ) 77 { 78 int temp = nums[numsSize-1]; 79 int i; 80 for( i=numsSize-1; i>0; i-- ) 81 { 82 nums[i] = nums[i-1]; 83 // printNums( nums, numsSize ); 84 } 85 nums[0] = temp; 86 k--; 87 // printNums( nums, numsSize ); 88 } 89 } 90 91 int main() 92 { 93 int nums[] = {1,2,3,4,5,6}; 94 int numsSize = 6; 95 int k = 2; 96 rotate2( nums, numsSize, k ); 97 98 return 0; 99 }