To find the area of a circle

• Topic background

calculation radius is 1 to the Ten the area of the circle, if the area is + to the - please output between

• Interface

int Outputrotundityarea ( float* Presultarray , int &arraycount )

float* Presultarray : Type float array

Int Arraycount : Array Length

• Specifications

Requires a time complexity of O (n)

π= 3.14

This problem is actually very simple, but the title and the download of the project file in the function parameters, the downloaded function prototype is:

#include <stdlib.h> #include <string.h> #include "oj.h"/* Function:    input:     output: Arrvalue: Stores the circle area within the returned range, Memory has been applied outside the function Nvalue: Returns the number of rows returned by the array     :      */void outputrotundityarea (float *arrvalue,int &nvalue) {}

The purpose of the topic is to calculate the area of a radius of 1-10, and then store the results of the matching criteria in an array, where it is easy to confuse the difference between the number of floating-point numbers and the size.

Full code:

#include <stdlib.h> #include <string.h> #include "oj.h"/* Function:    input:     output: Arrvalue: Stores the circle area within the returned range, Memory has been applied outside the function Nvalue: Returns the number of rows returned by the array     :      */void outputrotundityarea (float *arrvalue,int &nvalue) {  nvalue=0;  float area;  for (int i=1;i<=10;i++)  {     area=3.14*i*i; if (area>=40&&area<=90) Arrvalue[nvalue++]=area;}  }

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To find the area of a circle