POJ 1503 解题报告

/*
ID: thestor1
LANG: C++
TASK: poj1503
*/
#include <iostream>
#include <fstream>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <limits>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <cassert>

using namespace std;

void add(string &sum, string &nums)
{
int carry = 0, s, i, j;
for (i = sum.size() - 1, j = nums.size() - 1; j >= 0; --i, --j)
{
s = sum[i] - '0' + nums[j] - '0' + carry;
sum[i] = '0' + (s % 10);
carry = s / 10;
}
assert(i >= 0);
while (carry)
{
s = sum[i] - '0' + carry;
sum[i] = '0' + (s % 10);
carry = s / 10;
i--;
}
assert (i >= 0);
}

int main()
{
string line;
string sum(103, '0');
while (cin >> line && line != "0")
{
add(sum, line);
}

int left = 0;
while (left < sum.size() && sum[left] == '0')
{
left++;
}

while (left < sum.size())
{
printf("%c", sum[left]);
left++;
}
printf("\n");
return 0;
}