D. Minesweeper 1D
time limit per test

2 seconds

memory limit per test

512 megabytes

input

standard input

output

standard output

Game "Minesweeper 1D" is played on a line of squares, the line's height is 1 square, the line's width is n squares. Some of the squares contain bombs. If a square doesn't contain a bomb, then it contains a number from 0 to 2 — the total number of bombs in adjacent squares.

For example, the correct field to play looks like that: 001*2***101*. The cells that are marked with "*" contain bombs. Note that on the correct field the numbers represent the number of bombs in adjacent cells. For example, field 2* is not correct, because cell with value 2 must have two adjacent cells with bombs.

Valera wants to make a correct field to play "Minesweeper 1D". He has already painted a squared field with width of n cells, put several bombs on the field and wrote numbers into some cells. Now he wonders how many ways to fill the remaining cells with bombs and numbers are there if we should get a correct field in the end.

Input

The first line contains sequence of characters without spaces s1s2... sn (1 ≤ n ≤ 106), containing only characters "*", "?" and digits "0", "1" or "2". If character si equals "*", then the i-th cell of the field contains a bomb. If character si equals "?", then Valera hasn't yet decided what to put in the i-th cell. Character si, that is equal to a digit, represents the digit written in the i-th square.

Output

Print a single integer — the number of ways Valera can fill the empty cells and get a correct field.

As the answer can be rather large, print it modulo 1000000007 (109 + 7).

Sample test(s)
input
?01???
output
4
input
?
output
2
input
**12
output
0
input
1
output
0
Note

In the first test sample you can get the following correct fields: 001**1, 001***, 001*2*, 001*10.

DP 给5种情况进行编号,0代表当前位置是0,1代表当前位置是1且左边有炸弹,2代表当前位置是1左边没有炸弹,3代表当前位置是2,4代表当前位置是炸弹

dp2[0] = dp1[0];

dp2[1] = dp1[4];

dp2[2] = dp1[0] + dp1[1] ;

dp2[3] = dp1[4];

dp2[4] = dp1[4] + dp1[2] + dp1[3];

注意边界和数据范围即可。

 #include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream> using namespace std; typedef long long ll; #define maxn 1000005
#define MOD 1000000007 char s[maxn];
int dp[][];
void solve() { int *dp1 = dp[],*dp2 = dp[];
dp1[] = strlen(s) != && (s[] == '' || s[] == '?');
dp1[] = s[] == '' || s[] == '?';
dp1[] = s[] == '*' || s[] == '?';
for(int i = ; i < strlen(s); ++i) {
if(s[i] == '?' || s[i] == '') {
if(i != strlen(s) - )
dp2[] = (dp1[] + dp1[]) % MOD;
dp2[] = dp1[];
}
if(s[i] == '?' || s[i] == '') {
if(i != strlen(s) - )
dp2[] = dp1[];
}
if(s[i] == '?' || s[i] == '') {
dp2[] = (dp1[] + dp1[]) % MOD;
}
if(s[i] == '?' || s[i] == '*') { dp2[] = ((ll)dp1[] + dp1[] + dp1[]) % MOD;
} swap(dp1,dp2);
for(int j = ; j <= ; ++j) dp2[j] = ;
} int ans = ;
for(int i = ; i <= ; ++i) { ans = (ans + dp1[i]) % MOD;
} printf("%d\n",ans);
} int main() {
//freopen("sw.in","r",stdin); scanf("%s",s); solve(); return ;
}

cf div2 237 D的更多相关文章

  1. cf div2 234 D

    D. Dima and Bacteria time limit per test 2 seconds memory limit per test 256 megabytes input standar ...

  2. 离线dfs CF div2 707 D

    http://codeforces.com/contest/707/problem/D 先说一下离线和在线:在线的意思就是每一个询问单独处理复杂度O(多少多少),离线是指将所有的可能的询问先一次都处理 ...

  3. cf div2 239 D

    D. Long Path time limit per test 1 second memory limit per test 256 megabytes input standard input o ...

  4. cf div2 236 D

    D. Upgrading Array time limit per test 1 second memory limit per test 256 megabytes input standard i ...

  5. cf div2 238 D

    D. Toy Sum time limit per test 1 second memory limit per test 256 megabytes input standard input out ...

  6. cf div2 238 c

    C. Unusual Product time limit per test 1 second memory limit per test 256 megabytes input standard i ...

  7. cf div2 235 D

    D. Roman and Numbers time limit per test 4 seconds memory limit per test 512 megabytes input standar ...

  8. cf div2 234 E

    E. Inna and Binary Logic time limit per test 3 seconds memory limit per test 256 megabytes input sta ...

  9. CF div2 D BFS

    http://codeforces.com/contest/676/problem/D 题目大意: 勇者去迷宫杀恶龙.迷宫是有n*m的方格子组成的.迷宫上有各种记号,这些记号表达着能走的方向.当且仅当 ...

随机推荐

  1. Factory Girl使用

    1.使用Rspec,详见http://www.cnblogs.com/fanxiaopeng/p/3563772.html 2.在gemfile中添加 #Gemfile group :developm ...

  2. Linux开机启动程序详解

    Linux开机启动程序详解我们假设大家已经熟悉其它操作系统的引导过程,了解硬件的自检引导步骤,就只从Linux操作系统的引导加载程序(对个人电脑而言通常是LILO)开始,介绍Linux开机引导的步骤. ...

  3. 解压vmlinuz和解压initrd(initramfs)

    有时就算只得到一个Linux kernel的rpm包或者直接是编译后的vmlinuz和initrd的binary文件,也需要了解其中的一些细节,可能需要去查找这些binary有没有将我想要的patch ...

  4. [转]Ubuntu 12.04开机自动挂载Windows分区

    [转]Ubuntu 12.04开机自动挂载Windows分区 http://www.cnblogs.com/A-Song/archive/2013/02/27/2935255.html 系统版本:Ub ...

  5. .net 使用validator做数据校验

    概述 在把用户输入的数据存储到数据库之前一般都要对数据做服务端校验,于是想到了.net自带的数据校验框架validator.本文对validator的使用方法进行介绍,并分析下校验的的原理. 使用va ...

  6. 37.altium designer中的class和rules?

    在布局布线工程中,遇到复杂工程时,难免要进行class和rules的设置,经过试验证明,class和rules的子目录是有优先级的.

  7. 【BZOJ 1997】[Hnoi2010]Planar

    Description Input Output   找到哈密尔顿环之后找到不在哈密尔顿环上的边 这些边如果同时在里面相交那他们同时在外面也相交,所以只能一外一内,这就变成了2-SAT,判一下就好了 ...

  8. STL之multiset

    参见http://www.cplusplus.com/reference/set/multiset/ template < class T,                            ...

  9. 《梦断代码》读书笔记第0篇——“软件时间”、“死定了”、“Agenda之魂“

    第0章  软件时间 在未读这本书前,刚看到名字觉得是本讲代码的书,后来老师说是一个个的故事,这引起了我的兴趣,于是我便速速开始了第0章的阅读,读完一遍大概能读懂在讲什么,可能由于是译过来的书,书里面一 ...

  10. 文本阴影text-shadow

    文本阴影text-shadow text-shadow可以用来设置文本的阴影效果. 语法: text-shadow: X-Offset Y-Offset blur color; X-Offset:表示 ...