7-81 Least Prefix (10分)

7-81 Least Prefix (10分)

 

Given a non-empty array of N integers A, please find the smallest integer P such that all the numbers in A are in the subarray A[0..P].

Input Format:

A positive number N, followed by a list of N non-negative integers less than 1000000. N is no larger than 1000000.

Output Format:

The smallest integer P.

Sample Input:

5
2 2 1 0 1

 

Sample Output:

3

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define maxsize 1000001

int main()
{
 int n;
 int i;
 scanf("%d",&n);
 int temp;
 int index;
 int *a=malloc(sizeof(int)*(maxsize+1));
 memset(a,0,maxsize*sizeof(int));
 for(i=0;i<n;i++)
 {
  scanf("%d",&temp);
  if(a[temp]==0)
  {
   a[temp]=1;
   index=i;
  }
  
 }
 
 printf("%d\n",index);
 
 return 0;
}