参照了nocow上的解法,照搬过来…… 易知一个数X在数列中在另一个数Y前,当且仅当X前缀小于Y或前缀相等X短,那么我们分布考虑,比如对于数48561: 5位上:10000~48560; 4位上:1000~4856; 3位上:100~485; 2位上:10~48; 1位上:1~4. 这样我们就得到了1..N中4856的位置,可以用这个来判错. 接下来的方法类似,为了使得我们的N满足要求,我们必须去找比48561大且前缀比其小的数,同样有: 6位上:100000~48569;  //注意红色部分比…

首先计算出k至少为第几位,如果m小于这个数,那么输出0 还有一种情况, 就是10的i次方的这种情况,如果i+1等于m,那么直接输出k,否则输出0 其他的情况,就是二分,然后判断计算其插入到k之前的数的个数与k至少的位数之和 #include <stdio.h> #include <math.h> #define LL unsigned long long LL d[20],k,m,s; int t; void init() { d[0]=1; for(int i=1;i<20…

可以推出规律  每一个数第一次出现的位置 和 n*10后出现的位置  要特殊考虑 是10的倍数的情况(10,100,1000, .......) 它的位置是不会改变的 #include<cstdio> #define uLL unsigned long long using namespace std; uLL a[30] = {}, b[30] = {1,10}; void init() { for(int i = 1; i <= 20; ++i) a[i] = a[i-1]*10 +…

题目链接 题意:求给定的字符串的最长回文子串 分析:做法是构造一个新的字符串是原字符串+反转后的原字符串(这样方便求两边回文的后缀的最长前缀),即newS = S + '$' + revS,枚举回文串中心位置,RMQ询问LCP = min (height[rank[l]+1] to height[rank[r]]),注意的是RMQ传入参数最好是后缀的位置,因为它们在树上的顺序未知,且左边还要+1. #include <cstdio> #include <algorithm> #in…

2071. Juice Cocktails Time limit: 1.0 secondMemory limit: 64 MB Once n Denchiks come to the bar and each orders a juice cocktail. It could be from 1 to 3 different juices in each cocktail. There are three juices in the bar: apple, banana and pineappl…

2073. Log Files Time limit: 1.0 secondMemory limit: 64 MB Nikolay has decided to become the best programmer in the world! Now he regularly takes part in various programming contests, attentively listens to problems analysis and upsolves problems. But…

2070. Interesting Numbers Time limit: 2.0 secondMemory limit: 64 MB Nikolay and Asya investigate integers together in their spare time. Nikolay thinks an integer is interesting if it is a prime number. However, Asya thinks an integer is interesting i…

2069. Hard Rock Time limit: 1.0 secondMemory limit: 64 MB Ilya is a frontman of the most famous rock band on Earth. Band decided to make the most awesome music video ever for their new single. In that music video Ilya will go through Manhattan standi…

2068. Game of Nuts Time limit: 1.0 secondMemory limit: 64 MB The war for Westeros is still in process, manpower and supplies are coming to an end and the winter is as near as never before. The game of thrones is unpredictable so Daenerys and Stannis…

2067. Friends and Berries Time limit: 2.0 secondMemory limit: 64 MB There is a group of n children. According to a proverb, every man to his own taste. So the children value strawberries and raspberries differently. Let’s say that i-th child rates hi…