vetor decrescente

#include <iostream>

using namespace std;

int main() {
    int maior;
    int tam;
    int vet[tam];


    cout << "Digite o tamanho da sequencia" << endl;
    cin >> tam;

    cout << "Digite o valor 1 da sequencia" << endl;
    cin >> vet[0];
    for (int i = 1; i <= (tam - 1); i++){
        cout << "Digite o valor " << i + 1 << " da sequencia" << endl;
        cin >> vet[i];
        if (vet[i] > vet[i - 1]){
            vet[(i - 1)] == vet[i];
        }
    }
        for (int i = 0; i <= (tam - 1); i++){
            cout << "\n" << vet[i] << endl;
    }

}