HDU3709 Balanced Number
来源:互联网 发布:网络博客游戏怎么举报 编辑:程序博客网 时间:2024/06/14 01:16
Balanced Number
Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 6338 Accepted Submission(s): 3026
Problem Description
A balanced number is a non-negative integer that can be balanced if a pivot is placed at some digit. More specifically, imagine each digit as a box with weight indicated by the digit. When a pivot is placed at some digit of the number, the distance from a digit to the pivot is the offset between it and the pivot. Then the torques of left part and right part can be calculated. It is balanced if they are the same. A balanced number must be balanced with the pivot at some of its digits. For example, 4139 is a balanced number with pivot fixed at 3. The torqueses are 4*2 + 1*1 = 9 and 9*1 = 9, for left part and right part, respectively. It's your job
to calculate the number of balanced numbers in a given range [x, y].
to calculate the number of balanced numbers in a given range [x, y].
Input
The input contains multiple test cases. The first line is the total number of cases T (0 < T ≤ 30). For each case, there are two integers separated by a space in a line, x and y. (0 ≤ x ≤ y ≤ 1018).
Output
For each case, print the number of balanced numbers in the range [x, y] in a line.
Sample Input
20 97604 24324
Sample Output
10897
Author
GAO, Yuan
Source
2010 Asia Chengdu Regional Contest
————————————————————————————————————
题目的意思是求一段区间里的平衡数的有几个,平衡数的定义是一个数以某一个数为中心,左右各算出数值*和中心的距离之和,如果一样就是。
思路:数位dp,先枚举以哪一位为中心,3位数组表示到len位置,以pos为中心的,和为sum的数有几个,dfs求解
#include <iostream>#include <cstring>#include <string>#include <vector>#include <queue>#include <cstdio>#include <set>#include <cmath>#include <map>#include <algorithm>#define INF 0x3f3f3f3f#define MAXN 10000005#define Mod 10001using namespace std;#define LL long longLL dp[20][20][2000];int a[100];LL dfs(int len,int pos,int sum,bool limit){ if(len<0) return sum==0; if(sum<0) return 0; if(dp[len][pos][sum]!=-1&&!limit) return dp[len][pos][sum]; int up=limit?a[len]:9; LL ans=0; for(int i=0; i<=up; i++) { ans+=dfs(len-1,pos,sum+i*(len-pos),limit&&i==up); } return limit?ans:dp[len][pos][sum]=ans;}LL solve(LL x){ if(x<0) return 0; int cnt=0; while(x>0) { a[cnt++]=x%10; x/=10; } LL ans=0; for(int i=cnt-1; i>=0; i--) ans+=dfs(cnt-1,i,0,1); return ans-(cnt-1);}int main(){ LL n,m; int T; memset(dp,-1,sizeof dp); for(scanf("%d",&T); T--;) { scanf("%lld%lld",&m,&n); printf("%lld\n",solve(n)-solve(m-1)); } return 0;}
阅读全文
0 0
- hdu3709 Balanced Number
- hdu3709 Balanced Number
- hdu3709 Balanced Number
- 【HDU3709】【Balanced Number】
- hdu3709: Balanced Number
- hdu3709 Balanced Number
- 【HDU3709】 Balanced Number
- HDU3709 Balanced Number
- HDU3709 Balanced Number 数位DP
- [HDU3709]Balanced Number && 数位DP
- hdu3709 Balanced Number 数位dp
- hdu3709---Balanced Number(数位dp)
- hdu3709 Balanced Number 数位dp
- 数位dp hdu3709 Balanced Number
- HDU3709 Balanced Number 数位DP
- hdu3709 Balanced Number 数位dp
- hdu3709——Balanced Number
- HDU3709 Balanced Number[数位DP]
- 多表查询
- JavaBean技术
- Spark on YARN 笔记
- Allegro中设置自定义外形的焊盘
- vi -t tag的配置过程
- HDU3709 Balanced Number
- java并发编程-同步类容器-ArrayBlockingQueue
- 异常处理:Idea打包maven项目报错找不到编译环境
- hdoj 2647 Reward(拓扑排序+队列)
- Local Mapping
- 赛码网编程练习题_2
- Java——集合框架
- springmvc字符编码过滤器CharacterEncodingFilter浅析
- 学习jQuey中的return false