Merge pull request #1023 from AlgorithmWithGod/khj20006

[20251002] BOJ / P2 / 수열과 쿼리 5 / 권혁준

Author: ShinHeeEul

khj20006/202510/02 BOJ P2 수열과 쿼리 5.md

@@ -0,0 +1,40 @@
+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+int N, Q, k, a[100001]{}, b[100000]{}, c[1000001]{};
+vector<tuple<int, int, int>> q;
+
+int main(){
+    cin.tie(0)->sync_with_stdio(0);
+    
+    cin>>N;
+    k = sqrt(N);
+    for(int i=0;i<N;i++) cin>>a[i];
+    cin>>Q;
+    q.resize(Q);
+    int t = 0;
+    for(auto &[l,r,_]:q) {
+        cin>>l>>r;
+        _ = t++;
+        l--, r--;
+    }
+    sort(q.begin(), q.end(), [](auto x, auto y) -> bool {
+        auto [al, ar, ax] = x;
+        auto [bl, br, bx] = y;
+        if(al/k == bl/k) return ar < br;
+        return al/k < bl/k;
+    });
+
+    int l = 0, r = -1, s = 0;
+    for(auto [pl,pr,x]:q) {
+        while(r < pr) if(!c[a[++r]]++) s++;
+        while(pr < r) if(!--c[a[r--]]) s--;
+        while(l < pl) if(!--c[a[l++]]) s--;
+        while(pl < l) if(!c[a[--l]]++) s++;
+        b[x] = s;
+    }
+    for(int i=0;i<Q;i++) cout<<b[i]<<'\n';
+
+}
+```