'commit'

TangDou/AcWing_TiGao/T6/RMQ/1273_XT_2.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+const int N = 200010, M = 18;
+/*
+输入样例：
+5 3
+4 12 3 6 7
+1 3
+2 3
+5 5
+
+答案：
+1
+3
+7
+*/
+int n, q;
+int w[N];
+int f[N][M];
+// 预处理
+void rmq() {
+    for (int j = 0; j < M; j++)                     // 注意是j在外层,类似于区间DP,长度在外层
+        for (int i = 1; i + (1 << j) - 1 <= n; i++) // i(行)在内层
+            if (j == 0)                             // base case 边界值
+                f[i][j] = w[i];
+            else
+                f[i][j] = __gcd(f[i][j - 1], f[i + (1 << j - 1)][j - 1]);
+}
+
+// 查询区间最大值
+int query(int l, int r) {
+    int len = r - l + 1;
+    int k = log2(len);
+    return __gcd(f[l][k], f[r - (1 << k) + 1][k]);
+}
+int main() {
+    // 加快读入
+    ios::sync_with_stdio(false), cin.tie(0);
+    cin >> n >> q;
+    for (int i = 1; i <= n; i++) cin >> w[i];
+    rmq();
+    while (q--) {
+        int l, r;
+        cin >> l >> r;
+        printf("%d\n", query(l, r));
+    }
+    return 0;
+}