expression must be a modifiable lvalue. Codecademy - c++

Question

Can someone help me fix this, I'm doing the Learn C++ class on Codecademy and it says, "expressions must be a modifiable lvalue." It says this inside every if statement that I wrote. It's the last number in all of them. My guess would be that there is a problem with the logical operators in them but I'm not sure how to fix them. Any help would be greatly appreciated.
#include <iostream>
#include <stdlib.h>
int main() {
srand (time(NULL));
int computer = rand() % 3 + 1;
int user = 0;
std::cout << "=================================\n";
std::cout << "rock paper scissors lizard spock!\n";
std::cout << "=================================\n";
std::cout << "1) ✊\n";
std::cout << "2) ✋\n";
std::cout << "3) ✌️\n";
std::cout << "4) Lizard\n";
std::cout << "5) Spock\n";
std::cout << "shoot!\n";
std::cin >> user;
if(computer == 1 && user == 2 || user = 5) {
std::cout << "Computer Chose Rock!\n";
std::cout << "You win!\n";
}
else if (computer == 1 && int user == 3 || int user == 4){
std::cout << "Computer Chose Rock!\n";
std::cout << "You lose.\n";
}
else{
std::cout << "Computer Chose Rock!\n";
std::cout << "Tie!\n";
}
if(computer == 2 && user == 3 || user = 4) {
std::cout << "Computer Chose Paper!\n";
std::cout << "You win!\n";
}
else if (computer == 2 && user == 1 || user == 5){
std::cout << "Computer Chose Paper!\n";
std::cout << "You lose.\n";
}
else{
std::cout << "Computer Chose Paper!\n";
std::cout << "Tie!\n";
}
if(computer == 3 && user == 1 || user = 5) {
std::cout << "Computer Chose Scissors!\n";
std::cout << "You win!\n";
}
else if (computer == 3 && user == 4 || user == 2){
std::cout << "Computer Chose Scissors!\n";
std::cout << "You lose.\n";
}
else{
std::cout << "Computer Chose Scissors!\n";
std::cout << "Tie!\n";
}
if(computer == 4 && user == 1 || user = 3) {
std::cout << "Computer Chose Lizard!\n";
std::cout << "You win!\n";
}
else if (computer == 4 && user == 2 || user == 5){
std::cout << "Computer Chose Lizard!\n";
std::cout << "You lose.\n";
}
else{
std::cout << "Computer Chose Lizard!\n";
std::cout << "Tie!\n";
}
if(computer == 5 && user == 4 || user = 2) {
std::cout << "Computer Chose Spock!\n";
std::cout << "You win!\n";
}
else if (computer == 5 && user == 3 || user == 1){
std::cout << "Computer Chose Spock!\n";
std::cout << "You lose.\n";
}
else{
std::cout << "Computer Chose Spock!\n";
std::cout << "Tie!\n";
}
}

Answer 1

First of all, you should be careful with == or != in if statements. Then you already specified that user is int and you can use it in if statements without its type because compiler thinks that you are trying to declare it again.You also can't use time(NULL) without including ctime library.
#include <iostream>
#include <stdlib.h>
#include <ctime>
int main() {
srand(time(NULL));
int computer = rand() % 3 + 1;
int user = 0;
std::cout << "=================================\n";
std::cout << "rock paper scissors lizard spock!\n";
std::cout << "=================================\n";
std::cout << "1) ✊\n";
std::cout << "2) ✋\n";
std::cout << "3) ✌️\n";
std::cout << "4) Lizard\n";
std::cout << "5) Spock\n";
std::cout << "shoot!\n";
std::cin >> user;
if (computer == 1 && user == 2 || user == 5) {
std::cout << "Computer Chose Rock!\n";
std::cout << "You win!\n";
}
else if (computer == 1 && user == 3 || user == 4) {
std::cout << "Computer Chose Rock!\n";
std::cout << "You lose.\n";
}
else {
std::cout << "Computer Chose Rock!\n";
std::cout << "Tie!\n";
}
if (computer == 2 && user == 3 || user == 4) {
std::cout << "Computer Chose Paper!\n";
std::cout << "You win!\n";
}
else if (computer == 2 && user == 1 || user == 5) {
std::cout << "Computer Chose Paper!\n";
std::cout << "You lose.\n";
}
else {
std::cout << "Computer Chose Paper!\n";
std::cout << "Tie!\n";
}
if (computer == 3 && user == 1 || user == 5) {
std::cout << "Computer Chose Scissors!\n";
std::cout << "You win!\n";
}
else if (computer == 3 && user == 4 || user == 2) {
std::cout << "Computer Chose Scissors!\n";
std::cout << "You lose.\n";
}
else {
std::cout << "Computer Chose Scissors!\n";
std::cout << "Tie!\n";
}
if (computer == 4 && user == 1 || user == 3) {
std::cout << "Computer Chose Lizard!\n";
std::cout << "You win!\n";
}
else if (computer == 4 && user == 2 || user == 5) {
std::cout << "Computer Chose Lizard!\n";
std::cout << "You lose.\n";
}
else {
std::cout << "Computer Chose Lizard!\n";
std::cout << "Tie!\n";
}
if (computer == 5 && user == 4 || user == 2) {
std::cout << "Computer Chose Spock!\n";
std::cout << "You win!\n";
}
else if (computer == 5 && user == 3 || user == 1) {
std::cout << "Computer Chose Spock!\n";
std::cout << "You lose.\n";
}
else {
std::cout << "Computer Chose Spock!\n";
std::cout << "Tie!\n";
}
}

Answer 2

In addition to what was already said (you should be careful not to confuse user = 5 and user == 5; you should not use the keyword int, because the compiler thinks it's a declaration), there is one another very important issue.
You have to learn about operator precedence. The logical AND has higher priority than OR and will be evaluated first:
computer == 1 && user == 2 || user == 5
is equivalent to
(computer == 1 && user == 2) || user == 5
which means if user == 5 holds true, the whole statement will return true. Even if computer != 1. And your code will output "computer chose rock", which is incorrect.
Change it to
computer == 1 && (user == 2 || user == 5)
And as a general rule, that many similar if statements is a very poor choice. I hope they cover that later in your course. Good luck!