6-4.c

日文版畅销书籍10天学会C语言的源程序。适合入门者学习使用。希望对大家有帮助。

#include <stdio.h>
#include <string.h>

main () {
	char c;
	char str[] = "Hello"; //埫崋壔偡傞暥帤楍
	char key[128] = "abc"; //埫崋僉乕
	int keylen; //埫崋僉乕偺暥帤偺挿偝
	int i = 0; //埫崋僉乕偺尰嵼埵抲傪昞偡

	int j = 0; //埫崋壔偡傞暥帤楍偺尰嵼埵抲傪昞偡
	char str_[256]; //埫崋偟偨暥帤楍傪奿擺偡傞曄悢

	printf("暥帤楍 \"%s\" 傪僉乕 \"%s\" 偱埫崋壔\n", str, key);
	
	//埫崋壔
	keylen = strlen(key);
	while (*(str+j) != '\0') {
		c = *(str+j) + key[i++];
		str_[j++] = c;
		if(i >= keylen) { i = 0; }
	}

	str_[j] = '\0';
	printf("埫崋暥帤楍 \"%s\" 傪僉乕 \"%s\" 偱暅崋壔\n", str_, key);
	printf("尨暥丗");

	//暅崋壔
	j = 0;
	i = 0;
	while (*(str_+j)) {
		c = *(str_+j) - key[i++];
		j++;
		if(i >= keylen) { i = 0; }
		printf("%c", c);
	}

	return 0;
}