Implement of LCS

#include<stdio.h>
#include<conio.h>
#include<string.h>
int i,j,m,n,c[20][20];
char x[20],y[20],b[20][20];
void print_LCS(int i,int j)
{
	if(i==0 || j==0)
		return;
	if(b[i][j]=='c')
	{
		print_LCS(i-1,j-1);
		printf("%c",x[i]);
	}
	else if(b[i][j]=='u')
		print_LCS(i-1,j);
	else
		print_LCS(i,j-1);
}
void LCS_Length()
{
	m=strlen(x);
	n=strlen(y);
	for(i=1;i<=m;i++)
		c[i][0]=0;
	for(j=0;j<=n;j++)
		c[0][j]=0;
	for(i=1;i<=m;i++)
		for(j=1;j<=n;j++)
		{
			if(x[i]==y[j])
			{
				c[i][j]=c[i-1][j-1]+1;
				b[i][j]='c';
			}
			else if(c[i-1][j]>=c[i][j-1])
			{
				c[i][j]=c[i-1][j];
				b[i][j]='u';
			}
			else
			{
				c[i][j]=c[i][j-1];
				b[i][j]='l';
			}
		}
		print_LCS(m,n);
}
void main()
{
	printf("enter 1st sequence:");
	gets(x);
	printf("\nEnter 2nd sequence:");
	gets(y);
	printf("\nThe Longest Common Subsequence is ");
	LCS_Length();
}