PAT A 1093. Count PAT's (25)
来源:互联网 发布:如何理解算法分析 编辑:程序博客网 时间:2024/05/19 18:39
题目
The string APPAPT contains two PAT's as substrings. The first one is formed by the 2nd, the 4th, and the 6th characters, and the second one is formed by the 3rd, the 4th, and the 6th characters.
Now given any string, you are supposed to tell the number of PAT's contained in the string.
Input Specification:
Each input file contains one test case. For each case, there is only one line giving a string of no more than 105 characters containing only P, A, or T.
Output Specification:
For each test case, print in one line the number of PAT's contained in the string. Since the result may be a huge number, you only have to output the result moded by 1000000007.
Sample Input:
APPAPT
Sample Output:
2
典型的dp问题,
到s[j]时,匹配到“PAT”的第i个元素位置时的匹配数表示为:num[i][j],则:
1、如果s[j]等于PAT[i],num[i][j]=num[i][j-1]+num[i-1][j];
2、否则,num[i][j]=num[i][j-1]。
对于取余为防止溢出,每当为情况1时取一次余即可。
代码:
#include <iostream>#include <algorithm>#include <string>#include <vector>using namespace std;int main(){string s;cin>>s;if(s.empty()){cout<<0;return 0;}char cf[3]={'P','A','T'};vector<vector<int>> num(3,vector<int>(s.size(),0));//num[i][j]表示到s[j]时匹配目标串cf[0~i]的匹配数if(s[0]=='P')//dpnum[0][0]=1;for(int i=1;i<s.size();i++)if(s[i]=='P')num[0][i]=num[0][i-1]+1;elsenum[0][i]=num[0][i-1];for(int i=1;i<3;i++)for(int j=1;j<s.size();j++)if(s[j]==cf[i]){num[i][j]=num[i][j-1]+num[i-1][j];num[i][j]%=1000000007;}elsenum[i][j]=num[i][j-1];cout<<num[2][s.size()-1];return 0;}
- PAT A 1093. Count PAT's (25)
- PAT A 1093. Count PAT's (25)
- PAT-A 1093. Count PAT's (25)
- PAT-A-1093. Count PAT's (25)
- Pat(A) 1093. Count PAT's (25)
- PAT-A 1093. Count PAT's
- PAT 1093. Count PAT's (25)
- pat 1093. Count PAT's (25)
- PAT 1093. Count PAT's (25)
- 【PAT】1093. Count PAT's (25)
- pat 1093. Count PAT's (25)
- PAT 1093. Count PAT's (25)
- PAT 1093. Count PAT's (25)(有意思)
- PAT--1093. Count PAT's (25)
- PAT 1093. Count PAT's (25)
- PAT甲级1093. Count PAT's (25)
- PAT 1093. Count PAT's (25)
- PAT 甲级 1093. Count PAT's (25)
- IOS crash之NSInvalidArgumentException
- vCloud Suite Deployment Configurations---vCloud 部署配置
- Android系统回顾(六):菜单
- 相比于MRv1,YARN带来的优势是什么?
- 猫猫学IOS(一)UI之Hello World与加法计算器
- PAT A 1093. Count PAT's (25)
- Android Fragment完全解析,关于碎片你所需知道的一切(一)
- JSON格式
- SGU - 355 - Numbers Painting (贪心)
- Spring注解详解
- SQL Server 动态SQL EXEC加括号与不加括号的一点小问题
- QT5.2新版本+VS2010平台搭建图文教程
- IE iframe文档模式继承关系
- 退出当前账号