xcode scanf不能正常工作c

Question

为什么这段代码无效？

基本点子：

每辆车可以有4人在里面。每列火车的第一辆车长10英尺，其后每辆长8英尺。 列车只能占据轨道总长度的25％。
目标是打印出可以填充火车轨道的最大人数，以及用户输入的最大轨道长度和最大列车长度。

//Roller Coaster Capacity 
//Justin Castillo, Section 1, COP 3223, 2/9/2013 
//This program calculates the maximum number of people that can be on the 
//track at one time. 

int main(void) { 

    int max_people_train; 
    int num_cars_train; 
    int total_num_trains; 
    int max_length_track; 
    int max_length_train; 
    int max_people_track; 
    int prev_max_people_track; 
    int prev_total_num_trains, i; 

    printf("Please enter the track length:\n"); 
    scanf("%d", &max_length_track); 

    printf("Please enter the max length of the train:\n"); 
    scanf("%d", &max_length_train); 

    for (i=10; i<=max_length_train; i+8) { 
     num_cars_train = ((i-10)/8 +1); 
     max_people_train = (num_cars_train)*4; 
     total_num_trains = max_length_track/i; 
     max_people_track = total_num_trains*max_people_train; 

     prev_max_people_track = prev_total_num_trains * max_people_train; 
     prev_total_num_trains = max_length_track/(i-8); 

     if (prev_max_people_track > max_people_track) 
      max_people_track = prev_max_people_track; 
    } 



    printf("Your ride can have at most %d people on the track,\n", max_people_track); 
    printf("This can be achieved with trains of %d cars.\n", num_cars_train); 


    system("pause"); 
    return 0; 
} 

Answer 1

我猜它有事情做与此：

for (i=10; i<=max_length_train; i+8) { 
// ============================^^^ WTF ? 

尝试：

for (i=10; i<=max_length_train; i+=8) {