report tan

TAN.cpp

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<iostream>
#define N 15
/*
struct point{
	int x;
	int y;
};
struct point p[N];
int area(struct point q1,struct point q2,struct point q3){
	return ((q1.x - q3.x)*(q2.y-q3.y)+(q2.x-q3.x)*(q3.y-q1.y));
}
void quicksort(int first,int last){
	int i,j,somewhere;
	struct point pivot,temp;
	if(first<last){
		somewhere = (first + last)/2;
		pivot.x = p[somewhere].x;
		pivot.y = p[somewhere].y;
		i = first;
		j = last;
		do{
			
			//while(atan(p[i].y/p[i].x) < atan(pivot.y/pivot.x))i++;
			//while(atan(p[i].y/p[i].x) > atan(pivot.y/pivot.x))j--;
			
			while(area(p[0],pivot,p[i])<0)i++;
			while(area(p[0],pivot,p[j])>0)j--;
			if(i<=j){
				temp=p[i];
				p[i]=p[j];
				p[j]=temp;
				i++;
				j--;
			}
		}while(i<=j);
		quicksort(first,j);
		quicksort(i,last);
	}
}
int GrahamScan(){
	int i, top ,min;
	struct point temp;
	min = 0;
	
	for(i=0;i<N;i++){
		if(p[i].y<p[min].y || p[i].y==p[min].y && p[i].x > p[min].x){
			min = i;
		}
	}
	temp = p[0];
	p[0]=p[min];
	p[min]=temp;
	quicksort(1,N-1);
	top = 1;
	for(i=2;i<N;i++){
		while(area(p[top-1],p[top],p[i])<=0)
			top--;
		top++;
		temp = p[top];
		p[top] = p[i];
		p[i] = temp;
	}
	return (top+1);
	
}
int main(){
	int result;
	int array1[] = {
		2,0,14,0,14,5,2,5,3,4,3,1,5,1,7,1,9,1,11,1,13,1,13,3,13,4,11,4,9,4
	};
	for(int i=0;i<15;i++){
		printf("\nx%d:",array1[i]);
		p[i].x = array1[i];
		printf("\ny%d:",array1[i]);
		p[i].y = array1[i+1];
	}
	
	result = GrahamScan();
	char xx;
	printf("%d\n",result);
	scanf_s("%c",&xx);
	
}*/

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<math.h>


struct point{int x,y;};
struct point p[N];


int area(struct point q1,struct point q2,struct point q3)
{
	return((q1.x-q3.x)*(q2.y-q3.y)+(q2.x-q3.x)*(q3.y-q1.y));
}

void quicksort(int first,int last)
{
	int i,j,somewhere;
	struct point pivot,temp;
	if(first<last)
	{
	somewhere=(first+last)/2;
	pivot=p[somewhere];
	i=first;
	j=last;
	do{
		while(area(p[0],pivot,p[i])<0)i++;
		while(area(p[0],pivot,p[j])>0)j--;
		//while(atan(p[i].y/p[i].x) < atan(pivot.y/pivot.x))i++;
		//while(atan(p[i].y/p[i].x) > atan(pivot.y/pivot.x))j--;
	if(i<=j)
		{temp=p[i];p[i]=p[j];p[j]=temp;
		i++;j--;
		}
	}while(i<=j);

	quicksort(first,j);
	quicksort(i,last);
	}
}

int GrahamScan()
{
	int i,top,min;
	struct point temp;

	min=0;		
	for(i=1;i<N;i++)
		if(p[i].y<p[min].y||p[i].y==p[min].y&&p[i].x>p[min].x)
			min=i;
	temp=p[0];
	p[0]=p[min];
	p[min]=temp;
	quicksort(1,N-1);
	top=1;
	for(i=2;i<N;i++)
	{
		while(area(p[top-1],p[top],p[i])<=0)
		top--;
		top++;
		temp=p[top];
		p[top]=p[i];
		p[i]=temp;
	}
	return(top+1);
}

void main(void)
{
	int i=0,k=0;

	int array1[] = {
		2,0,14,0,14,5,2,5,3,4,3,1,5,1,7,1,9,1,11,1,13,1,13,3,13,4,11,4,9,4
	};

	/*
	for(i=0;i<N;i++){
		printf("%dx：",i);
		scanf_s("%d",&p[i].x);
		printf("%dy：",i);
		scanf("%d",&p[i].y);
	}
	*/

	for(int i=0;i<15;i++){
		printf("\nx:%d",array1[i]);
		p[i].x = array1[i];
		printf("\ny:%d",array1[i]);
		p[i].y = array1[i+1];
	}
	k=GrahamScan();
	printf("\nRESULT:%d",k);

	char xx;
	scanf_s("%c",&xx);
}