最长公共子序列

#include <iostream>
using namespace std;
char x[1005],y[1005];
int b[1005][1005];
int c[1005][1005];
void LSClength(int m,int n){
    int i,j;
    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]=1;
            }else if(c[i-1][j]>=c[i][j-1]){
                c[i][j]=c[i-1][j];
                b[i][j]=3;
            }else
            {
                c[i][j]=c[i][j-1];
                b[i][j]=2;
            }
}
void LSC(int i,int j){
    if(i==0||j==0)  return;
    if(b[i][j]==1){
        LSC(i-1,j-1);
        cout<<x[i];
    }else if(b[i][j]==2)
        LSC(i,j-1);
    else
        LSC(i-1,j);
    
}
int main(){
    memset(c,0,sizeof(c));
    memset(b,0,sizeof(b));
    memset(x,‘0‘,sizeof(x));
    memset(y,‘0‘,sizeof(y));
    while(cin>>x>>y){
        int m=strlen(x);
        int n=strlen(y);
        for(int i=m;i>0;i--)
           x[i]=x[i-1];
        for(int j=n;j>0;j--)
            y[j]=y[j-1];
        LSClength(m,n);
        LSC(m,n);
        
    }
    return 0;
}