1 files changed, 71 insertions, 0 deletions
diff --git a/21/open/ucfj.cpp b/21/open/ucfj.cpp
new file mode 100644
index 0000000..e7d7475
--- /dev/null
+++ b/21/open/ucfj.cpp
@@ -0,0 +1,71 @@
+#include <bits/stdc++.h>
+#define f first
+#define s second
+using namespace std;
+using ll = long long;
+using ii = pair<int, int>;
+constexpr int MX = 2e5+5;
+
+int b[MX], l[MX], s[MX];
+
+struct fenwick_tree {
+	int FT[MX];
+	fenwick_tree() { memset(FT, 0, sizeof FT); }
+	inline void update(int x, int v) { if (++x) for (; x < MX; x += x&-x) FT[x] += v; }
+	inline int query(int x) { int ret = 0; if (++x) for (; x; x -= x&-x) ret += FT[x]; return ret; }
+	inline int query(int x, int y) { return query(y)-query(x-1); }
+} range;
+
+struct seg_tree {
+	ll seg[4*MX], tmp[4*MX];
+	seg_tree() { memset(seg, 0, sizeof seg), memset(tmp, 0, sizeof tmp); }
+	inline ll pull(ll a, ll b) { return a+b; }
+	inline void push(int l, int r, int n) {
+		if (tmp[n]) {
+			seg[n] += range.query(l, r) * tmp[n];
+			if (l != r) tmp[n<<1] += tmp[n], tmp[n<<1|1] += tmp[n];
+			tmp[n] = 0;
+		}
+	}
+	void update(int a, int b, ll v, int l = 0, int r = MX-1, int n = 1) {
+		push(l, r, n);
+		if (l > r || l > b || r < a) return;
+		if (l >= a && r <= b) { tmp[n] += v, push(l, r, n); return; }
+		int m = l+r>>1;
+		update(a, b, v, l, m, n<<1), update(a, b, v, m+1, r, n<<1|1);
+		seg[n] = pull(seg[n<<1], seg[n<<1|1]);
+	}
+	ll query(int a, int b, int l = 0, int r = MX-1, int n = 1) {
+		if (a > b || l > b || r < a) return 0;
+		push(l, r, n);
+		if (l >= a && r <= b) return seg[n];
+		int m = l+r>>1;
+		return pull(query(a, b, l, m, n<<1), query(a, b, m+1, r, n<<1|1));
+	}
+} seg;
+
+int main() {
+	if (fopen("in", "r")) freopen("in", "r", stdin), freopen("out", "w", stdout);
+	cin.tie(0)->sync_with_stdio(0);
+
+	int N; cin >> N;
+	for (int i = 0; i < N; ++i) cin >> b[i];
+
+	memset(l, -1, sizeof l), memset(s, -1, sizeof s);
+	ll ans = 0;
+	for (int i = 0; i < N; ++i) {
+		if (l[b[i]] == -1) {
+			seg.update(0, i-2, 1);
+		}
+		else {
+			seg.update(s[b[i]]+1, l[b[i]]-1, -1);
+			seg.update(l[b[i]], l[b[i]], -seg.query(l[b[i]], l[b[i]]));
+			seg.update(l[b[i]]+1, i-2, 1);
+			range.update(l[b[i]], -1);
+		}
+		range.update(i, 1);
+		ans += seg.query(l[b[i]]+1, i-1);
+		s[b[i]] = l[b[i]], l[b[i]] = i;
+	}
+	cout << ans;
+}