1140. Look-and-say Sequence (20)

男娘i 2022-05-28 08:54 168阅读 0赞

**Look-and-say sequence** is a sequence of integers as the following:

D, D1, D111, D113, D11231, D112213111, ...

where D is in \[0, 9\] except 1. The (n+1)st number is a kind of description of the nth number. For example, the 2nd number means that there is one D in the 1st number, and hence it is D1; the 2nd number consists of one D (corresponding to D1) and one 1 (corresponding to 11), therefore the 3rd number is D111; or since the 4th number is D113, it consists of one D, two 1's, and one 3, so the next number must be D11231. This definition works for D = 1 as well. Now you are supposed to calculate the Nth number in a look-and-say sequence of a given digit D.

**Input Specification:**

Each input file contains one test case, which gives D (in \[0, 9\]) and a positive integer N (<=40), separated by a space.

**Output Specification:**

Print in a line the Nth number in a look-and-say sequence of D.

**Sample Input:**

1 8

**Sample Output:**

1123123111

--------------------

题目大意：

代码：

#include<stdio.h>
    int a[100000],b[100000],l1,l2;
    int main()
    {
        int i,j,n,m,k,t,num;
        scanf("%d %d",&n,&m);
        a[0]=n;
        l1=1;
        for(i=1;i<m;i++)
        {
            l2=0;
            for(j=0;j<l1;j++)
            {
                if(j==0)
                {
                    num=1;
                }
                else
                {
                    if(a[j]==a[j-1])
                    {
                        num++;
                    }
                    else
                    {
                        b[l2++]=a[j-1];
                        b[l2++]=num;
                        num=1;
                    }
                }
            }
            b[l2++]=a[j-1];
            b[l2++]=num;
            l1=l2;
            //printf("%d\n",l1);
            for(j=0;j<l2;j++)
            {
                a[j]=b[j];
            }
        }
    
        for(i=0;i<l1;i++)
        {
            printf("%d",a[i]);
        }
        return 0;
    }