maximum length snake sequence

#include<bits/stdc++.h>
using namespace std;
stack<pair<int,int> >calcPath(vector<vector<int> >&dp,int row,int column){
    pair<int,int>pt;
    stack<pair<int,int> >st;
    st.push({row,column});
    pt={row,column};
    while(dp[pt.first][pt.second]!=0){
        int i=pt.first;
        int j=pt.second;
        if(i>0&&(dp[i-1][j]+1==dp[i][j])){
            st.push({i-1,j});
            pt={i-1,j};
        }
        else if(j>0&&(dp[i][j-1]+1==dp[i][j])){
            st.push({i,j-1});
            pt={i,j-1};
        }
    }
    return st;
}

stack<pair<int,int> > findMaxPath(vector<vector<int> >&v){
    int m=v.size();
    int n=v[0].size();
    vector<vector<int> >dp(m,vector<int>(n,0));
    int max_row=0;
    int max_column=0;
    int max_length=0;
    for(int i=0;i<m;i++){
        for(int j=0;j<n;j++){
            if(i||j){

                if(j>0&&(abs(v[i][j-1]-v[i][j])==1)){
                    dp[i][j]=max(dp[i][j],dp[i][j-1]+1);
                    if(dp[i][j]>max_length){
                        max_row=i;
                        max_column=j;
                        max_length=dp[i][j];
                    }
                }
                if(i>0&&(abs(v[i-1][j]-v[i][j])==1)){
                    dp[i][j]=max(dp[i][j],dp[i-1][j]+1);
                    if(dp[i][j]>max_length){
                        max_row=i;
                        max_column=j;
                        max_length=dp[i][j];
                    }
                }
            }
        }
    }

    stack<pair<int,int> >path=calcPath(dp,max_row,max_column);
    return path;
}

int main(){
    int m, n;
    cin>>m>>n;
    vector<vector<int> >v(m);
    for(int i=0;i<m;i++){
        for(int j=0;j<n;j++){
            int c;
            cin>>c;
            v[i].push_back(c);
        }
    }
    stack<pair<int,int> >st=findMaxPath(v);
    while(!st.empty()){
        cout<<v[st.top().first][st.top().second]<<" ";
        st.pop();
    }
    return 0;
}