CSDN上能够找到很多道格拉斯普克算法的代码：其中一个
参考代码
1 #include<stdio.h> 2 #include<math.h> 3 #include<malloc.h> 4 #include<string.h> 5 #define NULL 0 6 #define LEN sizeof(struct point) 7 8 struct point 9 { 10 char ptname[8]; 11 float x; 12 float y; 13 struct point *next; 14 }; 15 16 struct point* creat(void) 17 { 18 struct point *head; 19 struct point *p1,*p2; 20 int n=0; 21 p1=p2=(struct point*)malloc(LEN); 22 scanf("%s",p1->ptname); 23 head=NULL; 24 while(strcmp(p1->ptname,"finish")!=0) 25 { 26 printf("请输入该点X Y坐标\n"); 27 scanf("%f%f",&p1->x,&p1->y); 28 n=n+1; 29 if(n==1) 30 head=p1; 31 else 32 p2->next=p1; 33 p2=p1; 34 p1=(struct point*)malloc(LEN); 35 printf("请输入下一点点名\n"); 36 scanf("%s",p1->ptname); 37 } 38 p2->next=NULL; 39 return(head); 40 } 41 42 struct point *getlast(struct point *p) 43 { 44 while(p->next!=NULL) 45 p=p->next; 46 return p; 47 } 48 49 float len(float x1,float y1,float x2,float y2,float x3,float y3) 50 { 51 float a,b,c,s,h; 52 a=sqrt((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2)); 53 b=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); 54 c=sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1)); 55 s=0.5*(a+b+c); 56 h=(sqrt(s*(s-a)*(s-b)*(s-c)))*2/c; 57 return h; 58 } 59 60 void doglas(struct point *head,struct point *last,float sigma) 61 { 62 struct point *hl;/*hl contains the remotest point C*/ 63 struct point *p=head->next; 64 float h,max=0; 65 while(p->next!=last) 66 { 67 h=len(head->x,head->y,p->x,p->y,last->x,last->y); 68 if(h>max) 69 { 70 max=h; 71 hl=p; 72 } 73 p=p->next; 74 } 75 if(max<=sigma) /*It is not a feature point*/ 76 { 77 head->next=last; 78 } 79 else /*It is a feature point*/ 80 { 81 doglas(head,hl,sigma); 82 doglas(hl,last,sigma); 83 } 84 } 85 86 void linkout(struct point *head) 87 { 88 struct point *p=head; 89 printf("点名 X Y\n"); 90 while(p) 91 { 92 printf("%s %f %f\n",p->ptname,p->x,p->y); 93 p=p->next; 94 } 95 } 96 void main() 97 { 98 printf("****************道格拉斯普克法******************\n"); 99 printf("################################################\n\n\n"); 100 float sigma; 101 printf("请输入阈值\n"); 102 scanf("%f",&sigma); 103 printf("请输入第一点点名,以'finish'结束输入\n"); 104 struct point *head; 105 head=creat(); 106 printf("\n\n您输入的点为:\n\n"); 107 linkout(head); 108 doglas(head,getlast(head),sigma); 109 printf("\n\n经道格拉斯普克法处理后的点为:\n"); 110 while(head!=NULL) 111 { 112 printf("%s ",head->ptname); 113 head=head->next; 114 } 115 printf("\n"); 116 }