Noob Tic-Tac-Toe Code

#include <iostream>
#include <fstream>
#include <stdio.h>
#include <conio.h>
#include <time.h>
using namespace std;

int aivall, aivaln;
char p1 = ' ', p2 = ' ', p3 = ' ', p4 = ' ', p5 = ' ', p6 = ' ', p7 = ' ', p8 =' ', p9 = ' ', l;
int n, endg = 0, again;

int ai(int a, int b) {
	if (a == 1) {
		switch (b) {
		case 1: {if (p1 == 88 || p1 == 79) {again = 1;} else {p1 = 79;}} break;
		case 2: {if (p2 == 88 || p2 == 79) {again = 1;} else {p2 = 79;}} break;
		case 3: {if (p3 == 88 || p3 == 79) {again = 1;} else {p3 = 79;}} break;
	}}
	if (a == 2) {
		switch (b) {
		case 1: {if (p4 == 88 || p4 == 79) {again = 1;} else {p4 = 79;}} break;
		case 2: {if (p5 == 88 || p5 == 79) {again = 1;} else {p5 = 79;}} break;
		case 3: {if (p6 == 88 || p6 == 79) {again = 1;} else {p6 = 79;}} break;
	}}
	if (a == 3) {
		switch (b) {
		case 1: {if (p7 == 88 || p7 == 79) {again = 1;} else {p7 = 79;}} break;
		case 2: {if (p8 == 88 || p8 == 79) {again = 1;} else {p8 = 79;}} break;
		case 3: {if (p9 == 88 || p9 == 79) {again = 1;} else {p9 = 79;}} break;
	}}

}

char xno(char p1, char p2, char p3, char p4, char p5, char p6, char p7, char p8, char p9) {
	cout << "    1  2  3 " << endl;
	cout << endl;
	cout << " A. " << p1 << "  " << p2 << "  " << p3 << endl;
	cout << endl;
	cout << " B. " << p4 << "  " << p5 << "  " << p6 << endl;
	cout << endl;
	cout << " C. " << p7 << "  " << p8 << "  " << p9 << endl;
	cout << endl;}

int triplecheckx() {
	//vertical
	if (p1 == 88 && p4 == 88 && p7 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
	if (p2 == 88 && p5 == 88 && p8 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
	if (p3 == 88 && p6 == 88 && p9 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}

	//Horizontal
	if (p1 == 88 && p2 == 88 && p3 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
	if (p4 == 88 && p5 == 88 && p6 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
	if (p7 == 88 && p8 == 88 && p9 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}

	//Cross
	if (p1 == 88 && p5 == 88 && p9 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
	if (p3 == 88 && p5 == 88 && p7 == 88) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Player Won!!!";
	}
}

int triplechecko() {
	//vertical
	if (p1 == 79 && p4 == 79 && p7 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
	if (p2 == 79 && p5 == 79 && p8 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
	if (p3 == 79 && p6 == 79 && p9 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}

	//Horizontal
	if (p1 == 79 && p2 == 79 && p3 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
	if (p4 == 79 && p5 == 79 && p6 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
	if (p7 == 79 && p8 == 79 && p9 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}

	//Cross
	if (p1 == 79 && p5 == 79 && p9 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
	if (p3 == 79 && p5 == 79 && p7 == 79) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "AI Won!!!";
	}
}

int checkalltie(char p1,char p2,char p3,char p4,char p5,char p6,char p7,char p8,char p9){
	if(p1 != 32 && p2 != 32 && p3 != 32 && p4 != 32 && p5 != 32 && p6 != 32 && p7 != 32 && p8 != 32 && p9 != 32 ) {
		endg = 1;
		system("cls");
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout<<"TIE!!!";}
}

int numberpick() {
	if (l == 'A') {
		switch (n) {
		case 1:
			p1 = 88;
			break;
		case 2:
			p2 = 88;
			break;
		case 3:
			p3 = 88;
			break;
		}
	}
	if (l == 'B') {
		switch (n) {
		case 1:
			p4 = 88;
			break;
		case 2:
			p5 = 88;
			break;
		case 3:
			p6 = 88;
			break;
		}
	}
	if (l == 'C') {
		switch (n) {
		case 1:
			p7 = 88;
			break;
		case 2:
			p8 = 88;
			break;
		case 3:
			p9 = 88;
		}
	}
}

int main() {
	ifendg1:
	checkalltie(p1,p2,p3,p4,p5,p6,p7,p8,p9);

	while (endg == 0) {
		srand(time(0));
		xno(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		cout << "Enter the position: ";
		cin >> l >> n;

		switch (l) {
		case 'A':
			numberpick();
		case 'B':
			numberpick();
		case 'C':
			numberpick();
		}

		checkalltie(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		triplecheckx();
		if(endg==1) goto ifendg1;

		repeat:

		again = 0;
		aivall = (rand() % 3) + 1;
		aivaln = (rand() % 3) + 1;
		ai(aivall, aivaln);
		triplechecko();
		if(endg==1) goto ifendg1;
		if (again == 1) {
			goto repeat;
		}
		dcheckalltie(p1,p2,p3,p4,p5,p6,p7,p8,p9);
		system("cls");
	}
}