poj2602

高精度加法，putchar(),getchar()比scanf(),printf()快。效率相差10多倍。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

#define maxn 1000006

int f1[maxn], f2[maxn];
char ans[maxn];

int main()
{
    //freopen("t.txt", "r", stdin);
    int n;
    scanf("%d", &n);
    getchar();
    for (int i = 0; i < n; i++)
    {
        f1[i] = getchar() - '0';
        getchar();
        f2[i] = getchar() - '0';
        getchar();
    }
    int temp = 0;
    for (int i = n - 1; i >= 0; i--)
    {
        ans[i] = ((f1[i] + f2[i] + temp) % 10) + '0';
        temp = (f1[i] + f2[i] + temp) / 10;
    }
    for (int i = 0; i < n; i++)
        putchar(ans[i]);
    putchar('\n');
    return 0;
}