Son longest string

5 longest common string (100)

Given two strings a, b, k prior chance in a string of characters to be modified, so that the longest common substring modified two longest string. Each modification can choose a, an arbitrary position in a string b modify an arbitrary character string.

Input formats:

The first line includes a positive integer k.
The second and third rows, respectively of the input string a, b. (The length of each string does not exceed 500)

Output formats:

Output is an integer representing the length of the longest common substring of two strings modified.

Sample input:

5
aaaaa
bbbbb

Sample output:

5

Accepted

#include <stdio.h>
#include <string.h> 
int main()
{   
    int k,i,j,len1,len2,t1,t2,sum,time,max=-1;
	char s1[505],s2[505]; 
    scanf("%d",&k);
    scanf("%s",&s1);
    scanf("%s",&s2);
    len1=strlen(s1);
    len2=strlen(s2);
for(i=0;i<len1;i++)
        for(j=0;j<len2;j++)
        {   
			t1=i;
            t2=j;
            sum=0;
            time=k;
            while(t1<len1&&t2<len2)
            {   
            while(t1<len1&&t2<len2&&s1[t1]==s2[t2])
              {
                t1++;
                t2++;
                sum++;
              }
              if(time>0)
              {  
	     t1++;
         t2++;
            sum++;
                time--;
              }
              else
              break;
             }
	 if(sum>max)
	 max=sum;   
        }  
    printf("%d",max);
    return 0; 
}

a [0], b [0] is the head, searching to find the maximum and maybe for the first string of first son, and a [0], b [1] ... then a [1], b [0] .. so, the maximum value of the sum is the maximum of all son string.