algorithm exercise

hanxin.cpp

#include <stdio.h>

#define TABLE_LENGTH 3 * 5 + 1

int table[3][TABLE_LENGTH] = {
	{ 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0 },
	{ 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 0 },
	{ 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1 }
};

int main()
{
	auto mod3Num = 0, mod5Num = 0, mod7Num = 0;
	while (~scanf("%d%d%d", &mod3Num, &mod5Num, &mod7Num))
	{
		auto beginEntry = 0;
		for (auto index = table[1][mod5Num]; index < TABLE_LENGTH; index += 5)
		{
			if (table[0][index] == mod3Num)
			{
				beginEntry = index;
				break;
			}
		}
		
		auto difference = (mod7Num - table[2][beginEntry] + 7) % 7;
		auto result = beginEntry + difference * 15;
		if (10 <= result && result <= 100)
		{
			printf("%d\n", result);
		}
		else
		{
			printf("No answer\n");
		}
	}
	return 0;
}