如何使用分治法求众数

Posted 2023-03-18

在一个数组里求出现次数最多的数为众数
请用分治法求众数
要求有具体代码

参考技术A #include<stdio.h>

int largest = 0; //the quantity
int element; //number
int a[10];
int med;

int median(int p,int r)

int s = r - p + 1;
if(s%2==0)
return a[s/2-1];
else
return a[s/2];


void split(int p,int r,int *p1,int *r1)

int i;
for(i=p;i<r;i++)

if(a[i]==med)

*p1 = i;
break;


for(i=*p1+1;i<r;i++)

if(a[i]!=med)

*r1 = i;
break;




void mode(int p,int r)

int *p1,*r1;
med = median(p,r);
split(p,r,p1,r1);
if(largest<*r1-*p1+1)

largest = *r1-*p1;
element = med;

if(*p1-1>largest)
mode(p,*p1-1);
if(r-*r1>largest)
mode(*r1+1,r);


void main()

int n,i,j;
FILE *fp1,*fp2;
fp1 = fopen("input.txt","r");
if(fp1==NULL)

printf("error\n");
return;

fscanf(fp1,"%d",&n);
printf("the quantuty of the number %d\n",n);
i = 0;
while(fp1!=NULL)

fscanf(fp1,"%d",&a[i]);
i++;
if(i>=n)
break;

for(i=0;i<n;i++)

printf("%d\t",a[i]);

printf("\n");
fclose(fp1);
mode(0,n);
fp2 = fopen("output.txt","w");
if(fp2==NULL)

printf("error\n");

fprintf(fp2,"%d\n%d",element,largest);
fclose(fp2);
参考技术B 要哪种语言的呀？ 参考技术C 要哪种语言的呀？