將一個字符串中的所有空格替換爲%20的源代碼及測試用例

#include <iostream>
#include <assert.h>

void ReplaceBlank(char string[],int capacity)//capacity爲數組str的總容量
{
	if (string == NULL || capacity <= 0)
		return;
	int length = 0;
	int blank_count = 0;
	int i = 0;
	while (string[i]!='\0')
	{
		length++;
		if (string[i] == ' ')
		{
			blank_count++;
		}
		i++;
	}

	int newLength = length + blank_count * 2;
	if (newLength > capacity)
		return;
	int indexOld = length;
	int indexNew = newLength;

	while (indexOld >= 0 && indexNew >= indexOld)
	{
		if (string[indexOld] == ' ')
		{
			string[indexNew--] = '0';
			string[indexNew--] = '2';
			string[indexNew--] = '%';
		}
		else
		{
			string[indexNew] = string[indexOld];
			indexNew--;
		}
		--indexOld;
	}
}


void Test(char* testName, char string[], int length, char expected[])
{
	if (testName != NULL)
		printf("%s begins: ", testName);

	ReplaceBlank(string, length);

	if (expected == NULL && string == NULL)
		printf("passed.\n");
	else if (expected == NULL && string != NULL)
		printf("failed.\n");
	else if (strcmp(string, expected) == 0)
		printf("passed.\n");
	else
		printf("failed.\n");
}

// 空格在句子中間
void Test1()
{
	const int length = 100;

	char string[length] = "hello world";
	Test("Test1", string, length, "hello%20world");
}

// 空格在句子開頭
void Test2()
{
	const int length = 100;

	char string[length] = " helloworld";
	Test("Test2", string, length, "%20helloworld");
}

// 空格在句子末尾
void Test3()
{
	const int length = 100;

	char string[length] = "helloworld ";
	Test("Test3", string, length, "helloworld%20");
}

// 連續有兩個空格
void Test4()
{
	const int length = 100;

	char string[length] = "hello  world";
	Test("Test4", string, length, "hello%20%20world");
}

// 傳入NULL
void Test5()
{
	Test("Test5", NULL, 0, NULL);
}

// 傳入內容爲空的字符串
void Test6()
{
	const int length = 100;

	char string[length] = "";
	Test("Test6", string, length, "");
}

//傳入內容爲一個空格的字符串
void Test7()
{
	const int length = 100;

	char string[length] = " ";
	Test("Test7", string, length, "%20");
}

// 傳入的字符串沒有空格
void Test8()
{
	const int length = 100;

	char string[length] = "helloworld";
	Test("Test8", string, length, "helloworld");
}

// 傳入的字符串全是空格
void Test9()
{
	const int length = 100;

	char string[length] = "   ";
	Test("Test9", string, length, "%20%20%20");
}

int main()
{
	Test1();
	Test2();
	Test3();
	Test4();
	Test5();
	Test6();
	Test7();
	Test8();
	Test9();

	return 0;
}