P.I. Works

#include <iostream>
#include<bits/stdc++.h>
using namespace std;

bool isPrime(int n){
    if(n==1||n==0){
        return false;
    }
    for(int i=2;i<=(n/2);++i){
        if(n%i==0){
            return false;
        }
    }
    return true;
}

int maxPathSum(int tri[100][100],int row,int column,int totalRows,int *sum){
    if(isPrime(tri[row][column])){
        return 0;
    }
    if(row==totalRows-1){
        *sum=tri[row][column];
        return 1;
    }
    int sum_1=0,sum_2=0,state=0;
    if(maxPathSum(tri,row+1,column,totalRows,&sum_1)){
        state=1;
    }
    if(maxPathSum(tri,row+1,column+1,totalRows,&sum_2)){
        state=1;
    }
    if(state){
        if(sum_1>sum_2){
            *sum=tri[row][column]+sum_1;
            return 1;
        }
        else{
            *sum=tri[row][column]+sum_2;
            return 1;
        }
    }
    else{
        return 1;
    }
}

int getNumberOfLines(char filename[]){
    string line;
    int count=0;
    ifstream file;
    file.open(filename);
    if(!file.is_open()){
        return 0;
    }
    while(getline(file,line)){
        count=count+1;
    }
    return count;
    file.close();
}

int main(void)
{
    char filename[100];
    cout<<"Please enter the input file name :"<<endl;
    cin>>filename;

    /*I assume maximum pyramid size is 100x100*/
    int tri[100][100]={0};
    int i;
    int j;
    ifstream file;
    file.open(filename);
    if(!file){
        cout<<"Error! Cannot open input file! "<<endl;
    }

    else{
        for(i=0;i<getNumberOfLines(filename);i++){
            for(j=0;j<=i;j++){
                file>>tri[i][j];
            }
        }

        /*To print the pyramid*/
        /*for(i=0;i<getNumberOfLines(filename);i++){
            for(j=0;j<=i;j++){
                cout<<tri[i][j]<<" ";
            }
            cout<<endl;
        }*/

        int sum;
        maxPathSum(tri,0,0,getNumberOfLines(filename),&sum);
        cout<<"The maximum possible sum of the pyramid is "<<sum<<"."<<endl;

    }

    file.close();
    return 0;
}