Hdu 1501 Zipper
2012-10-10 21:16
169 查看
Zipper
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4209 Accepted Submission(s): 1513
[align=left]Problem Description[/align]
Given three strings, you are to determine whether the third string can be formed by combining the characters in the first two strings. The first two strings can be mixed arbitrarily, but each must stay in its original order.
For example, consider forming "tcraete" from "cat" and "tree":
String A: cat
String B: tree
String C: tcraete
As you can see, we can form the third string by alternating characters from the two strings. As a second example, consider forming "catrtee" from "cat" and "tree":
String A: cat
String B: tree
String C: catrtee
Finally, notice that it is impossible to form "cttaree" from "cat" and "tree".
[align=left]Input[/align]
The first line of input contains a single positive integer from 1 through 1000. It represents the number of data sets to follow. The processing for each data set is identical. The data sets appear on the following lines, one data
set per line.
For each data set, the line of input consists of three strings, separated by a single space. All strings are composed of upper and lower case letters only. The length of the third string is always the sum of the lengths of the first two strings. The first two
strings will have lengths between 1 and 200 characters, inclusive.
[align=left]Output[/align]
For each data set, print:
Data set n: yes
if the third string can be formed from the first two, or
Data set n: no
if it cannot. Of course n should be replaced by the data set number. See the sample output below for an example.
[align=left]Sample Input[/align]
3
cat tree tcraete
cat tree catrtee
cat tree cttaree
[align=left]Sample Output[/align]
Data set 1: yes
Data set 2: yes
Data set 3: no
[align=left]Source[/align]
Pacific Northwest 2004
[align=left]Recommend[/align]
linle
#include<stdio.h> char a[201],b[201],c[402]; int visit[201][201]={0}; //剪枝 int isOk=0; void dfs(int i,int j,int k) { if(visit[i][j]==1) return; //剪枝 if(c[k]=='\0') { isOk=1; return; } if(a[i]!='\0'&&c[k]==a[i]) dfs(i+1,j,k+1); if(b[j]!='\0'&&c[k]==b[j]) dfs(i,j+1,k+1); visit[i][j]=1; //剪枝 } int main() { int n,i,j,cnt=0; // int flag=0; // freopen("d:\\data.in.txt","r",stdin); scanf("%d",&n); while(n--) { isOk=0; for(i=0;i<201;i++) //剪枝 for(j=0;j<201;j++) //剪枝 visit[i][j]=0; //剪枝 scanf("%s%s%s",a,b,c); dfs(0,0,0); printf("Data set %d: %s\n",++cnt,isOk?"yes":"no"); } return 0; }
感觉dp应该更快,就写了个dp的程序,结果比dfs还慢,应该是程序样例给的太简单,没有出复杂的数据。
#include<stdio.h> #include<string.h> #define MAXN 204 char a[MAXN],b[MAXN],c[2*MAXN]; int d[MAXN][MAXN]; int main(void) { int T,i,j,t; int d1,d2,d3; t=1; // freopen("d:\\in.txt","r",stdin); scanf("%d",&T); while(T--) { scanf("%s%s%s",a,b,c); d1=strlen(a); d2=strlen(b); for(i=0;i<=d1;i++) for(j=0;j<=d2;j++) d[i][j]=0; d[0][0]=1; for(i=1;i<=d1;i++) { if(a[i-1]==c[i-1]) d[i][0]=1; else break; } for(i=1;i<=d2;i++) { if(b[i-1]==c[i-1]) d[0][i]=1; else break; } for(i=1;i<=d1;i++) for(j=1;j<=d2;j++) { if(d[i][j-1] && b[j-1]==c[i+j-1]) d[i][j]=1; if(d[i-1][j] && a[i-1]==c[i+j-1]) d[i][j]=1; } printf("Data set %d: ",t++); if(d[d1][d2]) printf("yes\n"); else printf("no\n"); } return 0; }
相关文章推荐
- Zipper - HDU 1501 dp
- HDU 1501 Zipper(DP,DFS)
- (step4.3.5)hdu 1501(Zipper——DFS)
- hdu1501 zipper【记忆化搜索】【动态规划】
- HDU-1501 Zipper DFS+记忆化搜索
- HDU:1501 Zipper(DFS+剪枝)
- hdu 1501 Zipper
- hdu 1501 Zipper
- hdu zipper 1501
- hdu 1501 Zipper 拉链
- HDU 1501 Zipper(DFS)
- hdu 1501 Zipper
- HDU 1501 Zipper(dfs)
- HDU-1501-Zipper
- 【hdu 1501】Zipper(最优子结构)
- HDU 1501 Zipper
- HDU 1501 Zipper(DP,DFS)
- HDU 1501 Zipper
- HDU 1501 Zipper 【DFS+剪枝】
- HDU 1501 Zipper 动态规划经典