P1011 [NOIP1998 提高组] 车站

列表找

#include <stdio.h>
#include <stdlib.h>

int fq(int x, int sorx) //sorx==1 a
{
    if (x == 1 || x == 2 || (sorx && x == 4) || (!sorx && x == 3))
        return 0;
    if ((x == 3 && sorx) || (x == 4 && !sorx))
        return 1;
    int *a = (int *)malloc(sizeof(int) * x);
    int *res = (int *)malloc(sizeof(int) * x);
    a[0] = a[1] = res[0] = 1;
    res[1] = 2;
    int j = 2, i;
    i = x - 5 + (sorx ? 0 : 1);
    while (j <= i)
    {
        a[j] = a[j - 1] + a[j - 2];
        res[j] = a[j] + res[j - 1];
        j += 1;
    }
    return res[i];
}

int main()
{
    int a, n, m, x;
    scanf("%d%d%d%d", &a, &n, &m, &x);
    if (x == 1 || x == 2)
    {
        printf("%d", a);
        return 0;
    }
    if (x == 3)
    {
        printf("%d", 2 * a);
        return 0;
    }
    int b = (m - (2 + fq(n - 1, 1)) * a) / fq(n - 1, 0);
    printf("%d", (2 + fq(x, 1)) * a + fq(x, 0) * b);
    return 0;
}

P1011 [NOIP1998 提高组] 车站