PTA 乙级 1074 宇宙无敌加法器

代码实现：

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

int main()
{
	char chart[21] = { 0 }, num1[21] = { 0 }, num2[21] = { 0 }, result[21] = { 0 };

	gets(chart), gets(num1), gets(num2);
	int len1 = strlen(num1), len2 = strlen(num2), len_chart = strlen(chart);
	for (int i = 0; i < len_chart; i++)
	{
		int n1 = (i < len1 ? (num1[len1 - i - 1] - '0') : 0);
		int n2 = (i < len2 ? (num2[len2 - i - 1] - '0') : 0);
		int base = chart[len_chart - i - 1] - '0';
		base = (base == 0 ? 10 : base);
		int n = n1 + n2;
		result[21 - i - 1] += n;
		result[21 - i - 2] += result[21 - i - 1] / base;
		result[21 - i - 1] %= base;
	}
	for (int i = 0; i < 21; i++)
		result[i] += '0';
	for (int i = 0; i < 21; i++)
		if (result[i] != '0'&&result[i] != 0)
		{
			puts(result + i);
			return 0;
		}
	printf("0");

	return 0;
}