Throwing cards away I UVA - 10935(底层实现循环队列)

传送门

题意：先将第一张牌扔出，将第二张牌插到队列末尾，直到没牌

题解：使用循环队列（底层）

//底层实现循环队列
#include<iostream>
#include<cstdio>

using namespace std;

const int maxn=55;

int cq[maxn],headcq,tailcq;

void pushcq(int v)
{
    cq[tailcq++]=v;
    tailcq%=maxn;
}

void popcq()
{
    headcq++;
    headcq%=maxn;
}

int frontcq()
{
    return cq[headcq];
}

int sizecq()
{
    return (tailcq+maxn-headcq)%maxn;
}

void initcq()
{
    headcq=tailcq=0;
}

int main()
{
    int n;
    while(~scanf("%d",&n)&&n){
        initcq();
        for(int i=1;i<=n;i++){
            pushcq(i);
        }
        printf("Discarded cards:");
        int nofirst=0;
        while(sizecq()>=2){
            if(nofirst){
                printf(",");
            }
            nofirst=1;
            printf(" %d",frontcq());
            popcq();
            pushcq(frontcq());
            popcq();
        }
        printf("\nRemaining card: %d\n",frontcq());
    }
    return 0;
}