我创建了一个结构数组作为全局变量。我在函数中初始化了数组，然后可以从那里打印出结构的元素。我的问题是，除了用于初始化数组的函数外，无法在另一个函数（在我的情况下为main（））中打印出数组的值。请问如何打印这些值？谢谢。
#include <stdio.h>
#include <stdlib.h>
/*
*
*/
typedef struct s{
char *value;
} S;
S list[2];
void function( ){
char val1[] = "val1";
char val2[] = "val2";
S v1 = {val1};
S v2 = {val2};
list[0] = v1;
list[1] = v2;
printf("%s\n", list[1].value); //prints val2
}
int main(int argc, char** argv) {
function();
printf("%s", list[1].value); //prints nonsense
return 0;
}
我尝试过的：
我修改了function（）以将list用作参数（function（list）），并在main（）中声明了list。没用
我修改了函数以返回列表（S * function（）），但没有用。
我使用了一个整数数组（而不是结构，即int list [2]，将其声明为全局变量并在function（）中对其进行了初始化），并且一切正常，这表明问题出在我我正在访问结构，但我无法弄清楚。
我搜索了互联网，但没有遇到类似的问题。
答案 0 :(得分：2)
在函数from random import randint
total_amount_of_cars_that_are_driving_to_work_districts = 26904
total_amount_of_cars_that_are_driving_to_main_districts = 21528
total_amount_of_cars_that_are_driving_to_hotspot_districts = 5376
cars_per_hour_to_hotspot_districts = None
cars_per_hour_to_work_districts = None
cars_per_hour_to_main_districts = None
def generate_new_data():
create_days()
generate_work_districts_distribution()
generate_hotspot_distributions()
generate_distributions_to_main()
def distribute_faster(cars, totals):
counts = {total: 0 for total in range(totals)}
while cars > 0:
adjust = cars > 5000 # totally arbitrary
change = 1
if adjust:
change = 5
choice = randint(0, totals - 1)
counts[choice] += change
cars -= change
return counts
def create_days():
"----Work districts setup----"
global distributed_cars_to_work
distributed_cars_to_work = []
global cars_per_hour_to_work_districts
cars_per_hour_to_work_districts = []
total_work_districts = []
all_working_districts_used = []
for amount_of_working_districts in range(0, 7):
all_working_districts_used.append(amount_of_working_districts)
for work_districts in all_working_districts_used:
total_work_districts.append(work_districts)
"----Main districts setup----"
global distributed_cars_to_main
distributed_cars_to_main = []
global cars_per_hour_to_main_districts
cars_per_hour_to_main_districts = []
total_main_districts = []
all_the_main_districts = []
for amount_of_main_districts in range(0, 45):
all_the_main_districts.append(amount_of_main_districts)
for main_districts in all_the_main_districts:
total_main_districts.append(main_districts)
"----Hotspot district setup----"
global distributed_cars_to_hotspot
distributed_cars_to_hotspot = []
global cars_per_hour_to_hotspot_districts
cars_per_hour_to_hotspot_districts = []
total_hotspot_districts = []
all_the_hotspot_districts = []
for amount_of_hotspot_districts in range(0, 4):
all_the_hotspot_districts.append(amount_of_hotspot_districts)
for hotspot_districts in all_the_hotspot_districts:
total_hotspot_districts.append(hotspot_districts)
def generate_work_districts_distribution():
random_distribution_to_work = distribute_faster(total_amount_of_cars_that_are_driving_to_work_districts, 8)
print("Amount of cars distributed to work stations: {}".format(random_distribution_to_work))
print(
".............................................................................................................")
for key, value in random_distribution_to_work.items():
distributed_cars_to_work.append(value)
(work_districts) = (CarsDistribution('work', [distributed_cars_to_work for x in range(num_cars)]) for num_cars in
distributed_cars_to_work)
for randomWork in work_districts:
cars_per_hour_to_work_districts.append([len(c) for c in randomWork.cars_per_hour.values()])
for if_i_want_to_see_cars_per_hour_in_24_hours_to_work in cars_per_hour_to_work_districts:
print(if_i_want_to_see_cars_per_hour_in_24_hours_to_work)
print("Total amount of car that got distributed to this work station: {}".format(
sum(if_i_want_to_see_cars_per_hour_in_24_hours_to_work)))
print("--------------------------------------------------------------------------------------------------")
print("===============================WORK DISTRIBUTION FINISHED=========================================")
def generate_distributions_to_main():
random_distribution_to_main = distribute_faster(total_amount_of_cars_that_are_driving_to_main_districts, 46) # 46!!
print("Amount of cars distributed to main stations: {}".format(random_distribution_to_main))
print(
".............................................................................................................")
for key, value in random_distribution_to_main.items():
distributed_cars_to_main.append(value)
(main_districts) = (CarsDistribution('main', [distributed_cars_to_main for x in range(num_cars)]) for num_cars in
distributed_cars_to_main)
for randomMain in main_districts:
cars_per_hour_to_main_districts.append([len(c) for c in randomMain.cars_per_hour.values()])
for if_i_want_to_see_cars_per_hour_in_24_hours_to_main in cars_per_hour_to_main_districts:
print(if_i_want_to_see_cars_per_hour_in_24_hours_to_main)
print("Total amount of car that got distributed to this main station: {}".format(
sum(if_i_want_to_see_cars_per_hour_in_24_hours_to_main)))
print("--------------------------------------------------------------------------------------------------")
print("===============================MAIN DISTRIBUTION FINISHED=========================================")
def generate_hotspot_distributions():
random_distribution_to_hotspot = distribute_faster(total_amount_of_cars_that_are_driving_to_hotspot_districts, 5)
print("Amount of cars distributed to hotspot stations: {}".format(random_distribution_to_hotspot))
print(
".............................................................................................................")
for key, value in random_distribution_to_hotspot.items():
distributed_cars_to_hotspot.append(value)
(hotspot_districts) = (CarsDistribution('hotspot', [distributed_cars_to_hotspot for x in range(num_cars)]) for
num_cars in distributed_cars_to_hotspot)
for randomHotspot in hotspot_districts:
cars_per_hour_to_hotspot_districts.append([len(c) for c in randomHotspot.cars_per_hour.values()])
for if_i_want_to_see_cars_per_hour_in_24_hours_to_hotspot in cars_per_hour_to_hotspot_districts:
print(if_i_want_to_see_cars_per_hour_in_24_hours_to_hotspot)
print("Total amount of car that got distributed to this hotspot station: {}".format(
sum(if_i_want_to_see_cars_per_hour_in_24_hours_to_hotspot)))
print("--------------------------------------------------------------------------------------------------")
print("============================HOTSPOT DISTRIBUTION FINISHED=========================================")
class CarsDistribution:
all_probabilities = {
"work":
# Hour:0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
(0.0, 0.0, 0.0, 0.0, 0.01, 0.05, 0.11, 0.19, 0.23, 0.2, 0.14, 0.05, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0),
"main":
# Hour:0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.01, 0.01, 0.02, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.08, 0.08,
0.08, 0.07, 0.06, 0.06, 0.05, 0.04),
"hotspot":
# Hour:0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.01, 0.02, 0.03, 0.04, 0.08, 0.1, 0.12, 0.13, 0.13, 0.11,
0.07, 0.05, 0.04, 0.03, 0.02, 0.01)
}
def __init__(self, type, cars):
total_length = len(cars)
self.cars_per_hour = {}
for hour, p in enumerate(self.all_probabilities[type]):
try:
self.cars_per_hour[hour] = [cars.pop() for i in range(int(p * total_length))]
except IndexError:
print('cars already exhausted at hour {}'.format(hour))
if cars:
print('{} left after distributing is finished'.format(len(cars)))
中，您将一个局部变量的地址分配给您的结构。从function返回后，该地址不再有效。您可以将其设置为function或对其进行动态分配。
static