POJ 3320

#include <iostream>
#include <set>
#include <map>
using namespace std;

unsigned int P;
set<unsigned int> ideaSet;
unsigned int idea[1000001];
int numOfIdea;
int main()
{
    scanf("%ud", &P);
    for(int i = 0; i < P; ++i)
    {
        scanf("%ud", &idea[i]);
        ideaSet.insert(idea[i]);
    }
    
    numOfIdea = ideaSet.size();
    int num = 0;
    map<unsigned int, unsigned int> mp;
    int s = 0;
    int t = 0;
    int res = P;
    for(;;)
    {
        while(num < numOfIdea && t < P)
        {
            if(mp[idea[t++]]++ == 0)
            {
                num++;
            }
        }
        if(num < numOfIdea)
            break;
        res = min(res, t - s);
        if(--mp[idea[s++]] == 0)
            --num;
    }
    printf("%d\n", res);
    
    return 0;
}