Submission #257487

#	Time	Username	Problem	Language	Result	Execution time	Memory
257487		mhy908	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	1279 ms	41336 KiB

snake_escaping

#include <bits/stdc++.h>
#define F first
#define S second
using namespace std;
typedef long long LL;

int len, n, q;
int arr[1050000], arrrv[1050000], dp[1050000], dprv[1050000];
char str[1050000], qu[30];

int q_query(){
    int temp=0, x=0, ret=0;
    for(int i=1; i<=len; i++){
        temp*=2, x*=2;
        if(qu[i]=='?')temp++, x++;
        if(qu[i]=='1')temp++;
    }
    for(int i=x; ; i=x&(i-1)){
        ret+=arr[temp^i];
        if(!i)break;
    }
    return ret;
}

int o_query(){
    int temp=0, x=0, ret=0;
    for(int i=1; i<=len; i++){
        temp*=2, x*=2;
        if(qu[i]=='1')temp++, x++;
        if(qu[i]=='?')temp++;
    }
    for(int i=x; ; i=x&(i-1)){
        int pc=__builtin_popcount(i);
        if(pc%2)ret-=dp[temp^i];
        else ret+=dp[temp^i];
        if(!i)break;
    }
    return ret;
}

int z_query(){
    int temp=0, x=0, ret=0;
    for(int i=1; i<=len; i++){
        temp*=2, x*=2;
        if(qu[i]=='0')temp++, x++;
        if(qu[i]=='?')temp++;
    }
    for(int i=x; ; i=x&(i-1)){
        int pc=__builtin_popcount(i);
        if(pc%2)ret-=dprv[temp^i];
        else ret+=dprv[temp^i];
        if(!i)break;
    }
    return ret;
}

int main(){
    scanf("%d %d", &len, &q);
    n=(1<<len);
    scanf("%s", str);
    for(int i=0; i<n; i++){
        arr[i]=(int)(str[i]-'0');
        arrrv[(~i)&(n-1)]=arr[i];
    }
    for(int i=0; i<n; i++)dp[i]=arr[i], dprv[i]=arrrv[i];
    for(int i=0; i<len; i++){
        for(int mask=0; mask<n; mask++){
            if(mask&(1<<i))dp[mask]+=dp[mask^(1<<i)];
            if(mask&(1<<i))dprv[mask]+=dprv[mask^(1<<i)];
        }
    }
    for(int j=1; j<=q; j++){
        memset(qu, 0, sizeof qu);
        scanf("%s", qu+1);
        int qn=0, zn=0, on=0;
        for(int i=1; i<=len; i++){
            if(qu[i]=='?')qn++;
            if(qu[i]=='0')zn++;
            if(qu[i]=='1')on++;
        }
        if(qn<=len/3)printf("%d\n", q_query());
        else if(on<=len/3)printf("%d\n", o_query());
        else printf("%d\n", z_query());
    }
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:58:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &len, &q);
     ~~~~~^~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:60:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", str);
     ~~~~~^~~~~~~~~~~
snake_escaping.cpp:74:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s", qu+1);
         ~~~~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 10 / 10
• Subtask 4: 53 / 53
• Subtask 5: 25 / 25