HDU 4315 Climbing the Hill [阶梯Nim]

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
typedef long long ll;
const int N=1005;
inline int read(){
    char c=getchar();int x=0,f=1;
    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}
    return x*f;
}

int n,k,a[N];
int main(){
    //freopen("in","r",stdin);
    while(scanf("%d%d",&n,&k)!=EOF){
        for(int i=1;i<=n;i++) a[i]=read();
        if(k==1) {puts("Alice");continue;}
        int sg=0;
        if(k!=2) a[0]=-1;
        else a[0]=0;
        for(int i=n;i>=1;i-=2) sg^= a[i]-a[i-1]-1;
        puts(sg ? "Alice" : "Bob");
    }
}