Inversion problem - key point

Given a linear table, how to invert the elements in it?Two integer variables i and j can be set, i points to the first element, j points to the last element, while exchanging the elements pointed to by i and j, and let i and j move toward each other until they meet, the implementation code is as follows.Suppose the elements are stored in the array a[ ], and left and right are the subscripts of the elements at both ends of the array.

for(int i=lefft,j=right;i<j;i++,j--){int temp=a[i];a[i]=a[j];a[j]=temp;}

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【Example 2-5】

(1) Move the front k(k

Only need to invert the entire array to satisfy the requirement that the front-end k elements are reversed and placed in the back-end of the array

(2) Move the front k(k

Only need to invert the front-end k elements, and then invert the entire array to satisfy the front-end k elements in the original order and put them in the back end of the array

(3) Move the elements in the array (X₀, X₁, ..., X_n-1) tobecomes (X_p, X_p+1, ..., X_n-1, X₀, X₁,...,X_p-1), that is, circularly shifted left by p(0

Only need to set 0～p-1 The element at the position is reversed, and then p～n-1Invert the elements of the position, and then invert the entire array.