HDU6103(枚举)

Kirinriki

Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 833    Accepted Submission(s): 327

Problem Description

We define the distance of two strings A and B with same length n is
disA,B=∑i=0n−1|Ai−Bn−1−i|
The difference between the two characters is defined as the difference in ASCII.
You should find the maximum length of two non-overlapping substrings in given string S, and the distance between them are less then or equal to m.

 

Input

The first line of the input gives the number of test cases T; T test cases follow.
Each case begins with one line with one integers m : the limit distance of substring.
Then a string S follow.

Limits
T≤100
0≤m≤5000
Each character in the string is lowercase letter, 2≤|S|≤5000
∑|S|≤20000

 

Output

For each test case output one interge denotes the answer : the maximum length of the substring.

 

Sample Input

15abcdefedcb

 

Sample Output

5
Hint
[0, 4] abcde[5, 9] fedcbThe distance between them is abs('a' - 'b') + abs('b' - 'c') + abs('c' - 'd') + abs('d' - 'e') + abs('e' - 'f') = 5
 

 

Source

2017 Multi-University Training Contest - Team 6

思路：

枚举每个位置作为分割两个字串的中点，特别注意有奇数与偶数的区别。

#include<cstdio>#include<iostream>#include<string.h>#include<math.h> #include<algorithm>using namespace std;int m;char str[5010];int sum[5010];int solve(int l){int ans=0;int s=0;int i=0,j=0;while(1){while(i<l&&s+sum[i]<=m){s+=sum[i];ans=max(ans,i-j+1);i++;}s-=sum[j];j++;if(j>=l) break;}return ans;}void work(int l){int ans=0;for(int i=0;i<l;i++){int c=0;//当以奇数方式分割 for(int j=1;j+i<l&&i-j>=0;j++){sum[c]=abs(str[j+i]-str[i-j]);c++;}ans=max(ans,solve(c));}for(int i=0;i<l;i++){int c=0;//当以偶数方式分割 for(int j=1;j+i-1<l&&i-j>=0;j++){sum[c]=abs(str[j+i-1]-str[i-j]);c++; }ans=max(ans,solve(c));}printf("%d\n",ans);} int main(){int t;scanf("%d",&t);while(t--){int len;scanf("%d",&m);scanf("%s",str);len=strlen(str);work(len);}} 

 

Kirinriki

Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 833    Accepted Submission(s): 327

Problem Description

We define the distance of two strings A and B with same length n is
disA,B=∑i=0n−1|Ai−Bn−1−i|
The difference between the two characters is defined as the difference in ASCII.
You should find the maximum length of two non-overlapping substrings in given string S, and the distance between them are less then or equal to m.

 

Input

The first line of the input gives the number of test cases T; T test cases follow.
Each case begins with one line with one integers m : the limit distance of substring.
Then a string S follow.

Limits
T≤100
0≤m≤5000
Each character in the string is lowercase letter, 2≤|S|≤5000
∑|S|≤20000

 

Output

For each test case output one interge denotes the answer : the maximum length of the substring.

 

Sample Input

15abcdefedcb

 

Sample Output

5
Hint
[0, 4] abcde[5, 9] fedcbThe distance between them is abs('a' - 'b') + abs('b' - 'c') + abs('c' - 'd') + abs('d' - 'e') + abs('e' - 'f') = 5
 

 

Source

2017 Multi-University Training Contest - Team 6