LCS 3 stringssssss

1 test case not getting passed

#include<bits/stdc++.h>

using namespace std;

string func(string x,string y){
int dp[1010][1010];

dp[0][0]=0;
for(unsigned int i=0;i<x.length();i++)dp[i][0]=0;
for(unsigned int j=0;j<y.length();j++)dp[0][j]=0;

for(unsigned int i=1;i<=x.length();i++)
for(unsigned int j=1;j<=y.length();j++){
    if(x[i-1]==y[j-1])
    dp[i][j]=1+dp[i-1][j-1];
    else
    dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
}

// for(int i=0;i<=x.length();i++){
// for(int j=0;j<=y.length();j++)
// cout<<dp[i][j]<<" ";
// cout<<endl;
// }

string xx="";
int i=x.length(),j=y.length();
while(i>0&&j>0){
    if(dp[i][j-1]==dp[i-1][j]&&dp[i-1][j]!=dp[i][j]){
        xx+=x[i-1];
        i--;j--;
    }else{
        if(dp[i-1][j]>dp[i][j-1])
        i--;
        else
        j--;
    }
}
reverse(xx.begin(),xx.end());
return xx;

}

int main(){

string x,y,z;
cin>>x>>y>>z;

string ss=func(x,y);
string sss=func(ss,z);

cout<<sss.length()<<endl;

return 0;

}

Actually u r doing it a wrong logic
u have to compare them simalteneously it will required a 3 d array of dp
for more understand check for this test case

axbcde
pbxqdhe
ywxz