P1816 忠诚

R42939065

problem/P1816/P1816.cpp

@@ -0,0 +1,64 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct node {
+    int l, r;
+    int min;
+
+    node() {
+        l = r = 0;
+        min = 0x3f3f3f3f;
+    }
+    node(int _l, int _r) {
+        l = _l;
+        r = _r;
+        min = 0x3f3f3f3f;
+    }
+} tr[100005 << 2];
+int n, m, x, y, a[100005];
+
+void pushup(int u) {
+    tr[u].min = min(tr[u << 1].min, tr[u << 1 | 1].min);
+}
+
+void build(int u, int l, int r) {
+    tr[u] = node(l, r);
+    if (l == r) {
+        tr[u].min = a[l];
+        return;
+    }
+    int mid = l + r >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+    pushup(u);
+}
+
+int query(int u, int l, int r) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        return tr[u].min;
+    }
+    int mid = tr[u].l + tr[u].r >> 1;
+    int ans = 0x3f3f3f3f;
+    if (l <= mid) {
+        ans = query(u << 1, l, r);
+    }
+    if (r > mid) {
+        ans = min(ans, query(u << 1 | 1, l, r));
+    }
+    return ans;
+}
+
+int main() {
+    cin >> m >> n;
+    for (int i = 1; i <= m; i++) {
+        cin >> a[i];
+    }
+    build(1, 1, m);
+    while (n--) {
+        cin >> x >> y;
+        cout << query(1, x, y) << ' ';
+    }
+    cout << endl;
+    return 0;
+}