#include <stdio.h> #define MAXL 100 typedef int KeyType; typedef char InfoType[10]; typedef struct { KeyType key; //KeyType为关键字的数据类型 InfoType data; //其他数据 } NodeType; typedef NodeType SeqList[MAXL]; //顺序表类型 int BinSearch(SeqList R,int n,KeyType k) { int low=0,high=n-1,mid; while (low<=high) { mid=(low+high)/2; if (R[mid].key==k) //查找成功返回 return mid+1; if (R[mid].key>k) //继续在R[low..mid-1]中查找 high=mid-1; else low=mid+1; //继续在R[mid+1..high]中查找 } return 0; } int main() { int i,n=11; int result; SeqList R; KeyType a[]= {12,18,24,35,47,50,62,83,90,115,134},x=90; for (i=0; i<n; i++) R[i].key=a[i]; result = BinSearch(R,n,x); if(result>0) printf("序列中第 %d 个是 %d\n",result, x); else printf("木有找到!\n"); return 0; }
(2)递归折半算法:#include <stdio.h>#define MAXL 100typedef int KeyType;typedef char InfoType[10];typedef struct{ KeyType key; //KeyType为关键字的数据类型 InfoType data; //其他数据} NodeType;typedef NodeType SeqList[MAXL]; //顺序表类型int BinSearch(SeqList R,int n,KeyType k){ int low=0,high=n-1,mid; while (low<=high) { mid=(low+high)/2; if (R[mid].key==k) //查找成功返回 return mid+1; if (R[mid].key>k) //继续在R[low..mid-1]中查找 high=mid-1; else low=mid+1; //继续在R[mid+1..high]中查找 } return 0;}int main(){ int i,n=11; int result; SeqList R; KeyType a[]= {12,18,24,35,47,50,62,83,90,115,134},x=100; for (i=0; i<n; i++) R[i].key=a[i]; result = BinSearch(R,n,x); if(result>0) printf("序列中第 %d 个是 %d\n",result, x); else printf("木有找到!\n"); return 0;}
测试:{12,18,24,35,47,50,62,83,90,115,134},x=90;
{12,18,24,35,47,50,62,83,90,115,134},x=47;
{12,18,24,35,47,50,62,83,90,115,134},x=100;
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