uva 11572 - Unique Snowflakes(Towpointer)

#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <map>

using namespace std;
const int N = 1000005;

int n, g
;

map<int, int> v;

void init() {
v.clear();
scanf("%d", &n);
for (int i = 0; i < n; i++) scanf("%d", &g[i]);
}

int solve() {
int l = 0, ans = 0;
for (int r = 0; r < n; r++) {
v[g[r]]++;
while (v[g[r]] == 2) v[g[l++]]--;
ans = max(r - l + 1, ans);
}
return ans;
}

int main() {
int cas;
scanf("%d", &cas);
while (cas--) {
init();
printf("%d\n", solve());
}
return 0;
}