commit

Random/usaco open 2016/262144.cpp

@@ -0,0 +1,35 @@
+/* Bismillahir Rahmanir Rahim */
+
+#include <bits/stdc++.h>
+
+#define rep(i, n)	for(int i=0;i<n;i++)
+#define repn(i, n)	for(int i=1;i<=n;i++)
+#define set(i, n)	memset(i, n, sizeof(i))
+
+#define pb	push_back
+
+using namespace std;
+
+const int N = 300000;
+const int K = 70;
+
+int dp[N][K], n, a[N];
+
+int main(){
+	freopen("262144.in", "r", stdin);
+	freopen("262144.out", "w", stdout);
+	scanf("%d", &n);
+	repn(i, n) scanf("%d", &a[i]);
+	int ret = 0;
+	for(int i=1;i<=n;i++){
+		for(int j=1;j<=65;j++){
+			if(a[i] == j) dp[i][j] = i;
+			else if(!dp[i][j-1] || !dp[ dp[i][j-1]-1 ][ j-1 ]) continue;
+			else dp[i][j] = dp[ dp[i][j-1]-1 ][ j-1 ];
+			ret = max(ret, j);
+		}
+	}
+	printf("%d\n", ret);
+	return 0;
+}
+