2-11 integer Array A1

Analysis of the problem, only to determine whether there are Ai = i in an array of integers, you can instead judge the linear array of integers, and (Ai = i is an over the origin of a line with a slope of 1) whether there is a point of intersection.

The presence of intersections has the following conditions

1, the slope of the integer array equals 1: or repeat or no intersection

2, the slope of the integer array is greater than 1: only if the smallest point of the integer array, located below the AI = I line, the maximum point of the integer array, is located in the AI = I this line above, there may be intersection

3, the slope of the integer array is less than 1: only if the smallest point of the integer array, located above the AI = I line, the maximum point of the integer array, is located in the AI = i this line below, there may be intersection

So:

if (A1 < 1)

{

if (a > N) return True;

else return False;

}

else if (A1 = = 1) return True;

Else

{

if (a < n) return ture;

else return False;

}

}

The problem is deduced: Finding the intersection point I.

First, if there is a intersection, when there is a point of intersection, use the binary method to find the intersection.