2018 ACM-ICPC 南京站 E Eva and Euro coins

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/fanbaobao829/article/details/83098581

#include <bits/stdc++.h>
using namespace std;
const int maxn=1e6+5;
char s[maxn],t[maxn],sum[maxn];
int n,k;
void up_date(int now)
{
    while(now<=n)
    {
        sum[now]=sum[now]^1;
        now+=(now)&(-now);
    }
}
int ask(int now)
{
    int res=0;
    while(now)
    {
        res=res^sum[now];
        now-=(now)&(-now);
    }
    return res;
}
int main()
{
    while(scanf("%d%d",&n,&k)!=EOF)
    {
        scanf("%s",s+1);
        scanf("%s",t+1);
        /*for(int i=1;i<=n;i++)
        {
            s[i]='0';
            t[i]='1';
        }*/
        memset(sum,0,sizeof(sum));
        if(k==1)
        {
            printf("Yes\n");
            continue;
        }
        int f=0;
        for(int i=1;i<=n-k+1;i++)
        {
            int tp=(ask(i-1)^ask(max(0,i-k)));
            if((s[i]!=t[i]&&tp==0)||(s[i]==t[i]&&tp==1))
                up_date(i);
        }
        for(int i=n-k+2;i<=n;i++)
        {
            int tp=(ask(i-1)^ask(max(0,i-k)));
            if((s[i]!=t[i]&&tp==0)||(s[i]==t[i]&&tp==1))
            {
                f=1;
                break;
            }
        }
        if(!f)
            printf("Yes\n");
        else
            printf("No\n");
    }
    return 0;
}
/*
6 2
000000
101101
8 3
10101010
01010101
*/