c - 如何将for循环改为while循环

Question

位于程序底部的 for(t = 0; t < tmax ...) 循环应该是一个 while 循环(例如 while (s.distance > 0)) 在高度大于 0 时运行。根据用户选择的推力，tmax 可能或可能不足以让着陆器着陆。 简而言之，我需要将for循环更改为while循环以加快燃料消耗。

#include "stdio.h"
#include <math.h>
#include "string.h"
#include "ctype.h"

struct _State //different to shorten variable names
{
    double mass;
    double thrust;
    double accel;
    double velo;
    double distance;
    double fuel;
    char gameMode; // variable for keeping track of selected mode (A - 65 - Autopilot / M - 77 - Manual)
};
typedef struct _State State;

double getThrust(State* s) // Accepts user input for thrust and validates it
{
    printf("Input Thrust bellow. \n--> ");
    scanf("%lf", &s->thrust);

    if (s->thrust < 0)
    {
        return 0;
    }
    else if (s->thrust > 45000)
    {
        return 45000;
    }
    else
        return s->thrust;
}
void Update(State* s, double t, double stepSize)
{
    const double gMoon = -1.6;
    //double mass = 9000;
    //double fuel = 1800;
    s->thrust = getThrust(s);
    s->mass = s->mass - (s->thrust / 3000);
    s->accel = (s->thrust / s->mass) + gMoon;
    s->velo += s->accel * stepSize;
    s->distance += s->velo * stepSize;
    s->fuel = s->fuel - (s->thrust / 3000);
}

void manualControl(State* s) //manual controll function
{
    printf("\nManual mode: on\n");
    printf("-----------------\n\n");

    if (s->distance == 0) // Sets height value to the initial height value for calculations
    {
        s->distance = 15000;
    }
    if (s->velo == 0) // Sets velocity value to the initial velocity value for calculations
    {
        s->velo = -325;
    }
}

void autopilotControl(State* s) // Autopilot controll function
{
    printf("\nAutopilot: on\n");
    printf("-----------------\n\n");
}

void modeHandler(State* s) // mode controller. Calls appropriate function depending on the mode selected
{
    if (s->gameMode == 65)
    {
        autopilotControl(s);
    }
    else if (s->gameMode == 77)
    {
        manualControl(s);
    }
}

void modeSelect(State* s) // modeSelect allows user to pick the game mode and validates their input.
{
    printf("-->  ");
    scanf("%c", &s->gameMode);
    s->gameMode = toupper(s->gameMode);

    if (s->gameMode == 65 || s->gameMode == 77)
    {
        modeHandler(s);
    }
    else
    {
        printf("\nInvalid input. Please try again!\n");
        scanf("%c", &s->gameMode);
        s->gameMode = toupper(s->gameMode);
        modeSelect(s);
    }
}

int main(void)
{
    State s = { 9000,0,0,-325,15000,1800 };
    printf("Welcome to the Lunar Lander simulation!\n\n");
    printf("Your goal is to land the vehicle safely on the moon.\n");
    printf("You will be provided with information about the lander\nbased on which you will have to make a decision about\nhow much force should be applied to slow the vehicle down.\n");
    printf("-----------------------------------------------------------\n\n");

    printf("Choose your game mode.\n(Type \"A\" for autopilot) or (\"M\" for manual mode)\n");
    modeSelect(&s);

    double t = 0;
    double tmax = 150;
    const double stepSize = 1;
    FILE* f = fopen("lander.csv", "wt");
    if (!f)
    {
        printf("Unable to open file.\n");
        system("pause");
        return 1;
    }
    for (t = 0; t < tmax; t++)
    {
        while (t < tmax)
        {
            fprintf(f, "%.2f,%.2f,%.2f,%.2f%.2f,\n", t, s.accel, s.velo, s.distance, s.fuel);
            Update(&s, t, stepSize);
            printf("Current height:   %.2f m\n", s.distance);
            printf("Current velocity: %.2f m/s\n", s.velo);
            printf("Fuel left :       %.2f kg\n", s.fuel);
            printf("---------------------------\n\n");


        }
    }
    system("pause");
}

这里是输出:

Choose your game mode.
(Type "A" for autopilot) or ("M" for manual mode)
-->  M

Manual mode: on
-----------------

Input Thrust bellow.
--> 20
Current height:   14673.40 m
Current velocity: -326.60 m/s
Fuel left :       1799.99 kg
---------------------------

Input Thrust bellow.
-->

Answer 1

似乎可以在 Update(...) 方法中定义燃料减量。那么，难道不应该定义类似以下建议的内容吗？

// ...
int t = 0;
int tmax = 150;
// ...
while ((s.fuel > 0.0) && (t < tmax))
{
     fprintf(f, "%.2f,%.2f,%.2f,%.2f%.2f,\n", t, s.accel, s.velo, s.distance, s.fuel);
     Update(&s, t, stepSize);
     printf("Current height:   %.2f m\n", s.distance);
     printf("Current velocity: %.2f m/s\n", s.velo);
     printf("Fuel left :       %.2f kg\n", s.fuel);
     printf("---------------------------\n\n");
     t++;   
}
// ...