poj1939

简单题

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

struct Point
{
    long long x, y;
}first, last, now;

int n;

void input()
{
    printf("%d ", n);
    scanf("%lld%lld", &first.x, &first.y);
    last = first;
    for (int i = 1; i < n; i++)
    {
        scanf("%lld%lld", &now.x, &now.y);
        printf("%.6f %.6f ", (last.x + now.x) / 2.0, (now.y + last.y) / 2.0);
        last = now;
    }
    now = first;
    printf("%.6f %.6f ", (last.x + now.x) / 2.0, (now.y + last.y) / 2.0);
    putchar('\n');
}

int main()
{
    //freopen("t.txt", "r", stdin);
    while (scanf("%d", &n) != EOF)
        input();
    return 0;
}