week16- B2. Two Swords Style Medium, Author Solution

#include<cstdio>
const int SIZE = 1<<20;
int dp[SIZE],a[SIZE];
int main(){
    int n,q;
    scanf("%d%d",&n,&q);
    for(int i=0;i<n;i++){
        char s[24];
        scanf("%s",s);
        for(int j=0;j<20;j++)a[i]|=(int)(s[j]-'0')<<j;
        dp[a[i]]++;
    }
    for(int i=0;i<20;i++)
        for(int j=0;j<SIZE;j++)
            if((j>>i)&1)dp[j^(1<<i)]+=dp[j];
    while(q--){
        long long an=0;
        int x=0;
        char s[24];
        scanf("%s",s);
        for(int j=0;j<20;j++)x|=(int)(s[j]-'0')<<j;
        for(int i=0;i<n;i++){
            an+=dp[x^(x&a[i])];
            if((x&a[i])==x)an--;
        }
        printf("%I64d\n",an/2);
    }
}