Problem C: floating point adder

Topic links : http://codeup.cn/problem.php?cid=100000593&pid=2

Description Title
seeking two floating-point addition and
floating-point number has the following form appears in the title of the input and output:
P1P2 ... ... Pi.Q1Q2 Qj
for the integer part, P1P2 ... Pi is a non-negative integer
to the fractional part, Qj not equal to 0

Input
For each case, the first row is a set of n number of test data, each set of test data occupies two rows, respectively, two addends.
A blank line between each set of test data, each row of data does not exceed 100 characters

Output
each case is n lines, each line the test data and the corresponding output.
Guaranteed output is not a fractional part of the floating-point number 0

Sample input
2
3.756
90.564

4543.5435
43.25

Sample Output
94.32
4586.7935

Code

#include<cstdio>
#include<cstring>

struct bign {
	int d[1001], x[1001];		//分别储存整数部分和小数部分
	int dlen, xlen;					//整数部分长度和小数部分
	bign() {
		memset(d, 0, sizeof(d));
		memset(x, 0, sizeof(x));
		dlen = 0, xlen = 0;
	}
};

bign charge(char str[]) {
	bign a;
	int i, j, t, len = strlen(str);
	for(i = 0; str[i] != '.'; i++);
	for(t = 0; t < i; t++)									 //整数从低位开始存
		a.d[t] = str[i - 1 - t] - '0';
	a.dlen = t;
	i++;
	for(j = 0; i < len; i++)									//小数从高位开始存（方便按位相加）
		a.x[j++] = str[i] - '0';
	a.xlen = j;
	return a;
}

bign add(bign a, bign b) {
	bign c;
	int carry1 = 0;
	int maxlen = (a.xlen >= b.xlen) ? a.xlen : b.xlen;
	c.xlen = maxlen;
	for(int i = maxlen - 1; i >= 0; i--) {				//小数相加
		int temp = a.x[i] + b.x[i] + carry1;
		c.x[i] = temp % 10;
		carry1 = temp / 10; 
	}
	while(c.x[c.xlen - 1] == 0)
		c.xlen--;
	int carry2 = carry1;										//小数的进位传给整数
	for(int i = 0; i < a.dlen || i < b.dlen; i++) {	//整数相加
		int temp = a.d[i] + b.d[i] + carry2;
		c.d[c.dlen++] = temp % 10;
		carry2 = temp / 10; 
	}
	if(carry2 != 0) {
		c.d[c.dlen++] = carry2;
	}
	return c;
}

void print(bign a) {
	for(int i = a.dlen - 1; i >= 0; i--)		//整数打印
		printf("%d", a.d[i]);
	if(a.xlen >= 1){
		printf(".");
		for(int i = 0; i < a.xlen; i++)			//小数打印
			printf("%d", a.x[i]);
	}
	printf("\n");
}

int main() {
	int n;
	char str1[1001], str2[1001];
	scanf("%d",&n);
	while(n > 0) {
		scanf("%s%s", str1, str2);
		bign a = charge(str1);
		bign b = charge(str2);
		print(add(a, b));
		n--;
	}
	return 0;
}