谁能来帮一下我这个猴子吃桃问题啊

int main()
{
    int i = 1;
    int j;
    scanf("%d",&j);
    for (j; j > 1;j --)
    {
        i++;
        i = 2 * i;
    }
    printf("%d", i);
}

#include <stdio.h>

int main() {
    int days;
    int howMany = 1;
    scanf("%d", &days);

    for (int i = 1; i < days; i++) {
        howMany++;
        howMany *= 2;

    }
    printf("%d", howMany);
}