Create 1068.cpp

hihoCoder/1068.cpp

@@ -0,0 +1,68 @@
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+#include <algorithm>
+#include <cmath>
+using namespace std;
+
+const int MAXN = 1000005;
+
+int n,ndev;
+int a[MAXN];
+
+const int MAXDEV = 25;
+
+int minsum[MAXN][MAXDEV];
+
+void RMQ() //预处理->O(nlogn)
+{
+    for(int j = 1; j <= ndev; ++j)
+        for(int i = 1; i <= n; ++i)
+            if(i + (1 << j) - 1 <= n)
+            {
+                //maxsum[i][j] = max(maxsum[i][j - 1], maxsum[i + (1 << (j - 1))][j - 1]);
+                minsum[i][j] = min(minsum[i][j - 1], minsum[i + (1 << (j - 1))][j - 1]);
+            }
+}
+int RMQ(int i,int j)
+{
+    int k=log2( j - i + 1);
+    //return max(maxsum[i ][ k], maxsum[ j - 2 ^ k + 1][ k]);
+    return min(minsum[i ][ k], minsum[ j - (1<<k) + 1][ k]);
+}
+void Init()
+{
+    for(int i=1;i<=n;i++)
+    {
+        minsum[i][0]=a[i];
+    }
+}
+int main()
+{
+    scanf("%d",&n);
+    ndev=0;
+    int p=n;
+    if(p&1) p++;
+    while(p>1)
+    {
+        p>>=1;
+        ndev++;
+    }
+    for(int i=1;i<=n;i++)
+    {
+        scanf("%d",&a[i]);
+    }
+    Init();
+    RMQ();
+    int t;
+    scanf("%d",&t);
+    for(int i=0;i<t;i++)
+    {
+        int L,R;
+        scanf("%d %d",&L,&R);
+        int ans=RMQ(L,R);
+        printf("%d\n",ans);
+    }
+    return 0;
+}