Add xiaobei

C++/SegTree_RMQ.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+using i64 = long long;
+
+void solve() {
+    int n; cin >> n;
+    vector<int> w(n + 1);
+    for (int i = 1; i <= n; i ++ ) 
+        cin >> w[i];
+    struct SegTree {
+        int l, r;
+        int val;
+    };
+    constexpr int inf = 0x3f3f3f3f;
+    vector<SegTree> tr(n << 2);
+    function<void(SegTree &, SegTree, SegTree)> push_up = [&] (SegTree &root, SegTree ls, SegTree rs) {
+        root.val = min(ls.val, rs.val);
+    };
+    function<void(int, int, int)> build = [&] (int root, int l, int r) {
+        tr[root].val = inf;
+        tr[root].l = l, tr[root].r = r;
+        if (l == r) return tr[root].val = w[l], void();
+        int mid = l + r >> 1;
+        build(root << 1, l, mid); build(root << 1 | 1, mid + 1, r);
+        push_up(tr[root], tr[root << 1], tr[root << 1 | 1]);
+    };
+    function<int(int, int, int)> query = [&] (int root, int l, int r) {
+        if (l <= tr[root].l && tr[root].r <= r) 
+            return tr[root].val;
+        int res = inf;
+        if (tr[root << 1].r >= l) res = min(res, query(root << 1, l, r));
+        if (tr[root << 1 | 1].l <= r) res = min(res, query(root << 1 | 1, l, r));
+        return res;
+    };
+    build(1, 1, n);
+    int m; cin >> m;
+    while (m -- ) {
+        int l, r; cin >> l >> r;
+        cout << query(1, l, r) << "\n"; 
+    }
+}
+
+int main (void) {
+    ios::sync_with_stdio(0);
+    cin.tie(0); cout.tie(0);
+    int T = 1; cin >> T;
+    while (T -- ) solve();
+    return 0;
+}