一次 scanf 或 getchar 10000 次然后程序在 c 中停止

Question

#include "stdio.h"

int main() {
    int ch,i;
     for (i = 0; i < 10000; ++i) {
        scanf(" %c", &ch);
        putchar(ch);
     }
     return 0;
}

如果你输入的字符少于 1000 个，它可以工作，但如果你一次输入 10000 个字符，程序就会停止。我可能认为这是因为标准输入缓冲区。我该如何解决这个问题？

这是更具体的来源。

#include "stdio.h"
#include "stdlib.h"

int main() {
    int i,n;
    char *p, ch;

    scanf("%d", &n);
    p = (char*) malloc(sizeof(char) *n);

    if (p == NULL) {
        return -1;
    }

    for (i = 0; i < n; ++i) {
        scanf(" %c", &ch);
        putchar(ch);
    }
    return 0;
}

住所来源为样本。 - 放 n （要阅读的字数）然后放长长的字符串。程序停止或等待完成某事。

输入示例 1.

2000 lsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdkalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalssdafsdfsdfdd

这个没用。

但下面的正在运行。 2.

1000 jsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdkalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalssdafsdfsdfddkdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalsdklsakdjldjsalkfjalssdafsdfsdfdd1

Answer 1

您的 for 循环可能如下所示：

for (i = 0; i < n; ++i) {
    scanf(" %c", &p[i]);
    putchar(p[i]);
}

您还可以尝试刷新代码中的 stdin 输入缓冲区，因为正确添加了以下行：

fflush(stdin);

编辑：由于在某些系统上可能存在未定义的行为，因此可以实现一种替代的和更常见的方法，如下所示：

int ch;

while((ch = getchar()) != EOF && ch != '\n') {

      // ...
}

或者您可以通过调用下面的 setvbuf 函数来正确更改流缓冲区大小：

int setvbuf (FILE* stream, char* buffer, int mode, size_t size);

一次 scanf 或 getchar 10000 次然后程序在 c 中停止

scanf or getchar 10000 times at a time then program stopped in c

c

scanf

getchar