Submission #45519

#	Time	Username	Problem	Language	Result	Execution time	Memory
45519		reality	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	1159 ms	65536 KiB

snake_escaping

#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
int D0[1 << 20];
int D1[1 << 20];
char str[1 << 20];
int coef[1 << 20];
inline int readChar();
template <class T = int> inline T readInt();
template <class T> inline void writeInt( T x, char end = 0 );
inline void writeChar( int x );
inline void writeWord( const char *s );

/** Read */

static const int buf_size = 4096;

inline int getChar() {
    static char buf[buf_size];
    static int len = 0, pos = 0;
    if (pos == len)
        pos = 0, len = fread(buf, 1, buf_size, stdin);
    if (pos == len)
        return -1;
    return buf[pos++];
}

inline int readChar() {
    int c = getChar();
    while (c <= 32)
        c = getChar();
    return c;
}

template <class T>
inline T readInt() {
    int s = 1, c = readChar();
    T x = 0;
    if (c == '-')
        s = -1, c = getChar();
    while ('0' <= c && c <= '9')
        x = x * 10 + c - '0', c = getChar();
    return s == 1 ? x : -x;
}

/** Write */

static int write_pos = 0;
static char write_buf[buf_size];

inline void writeChar( int x ) {
    if (write_pos == buf_size)
        fwrite(write_buf, 1, buf_size, stdout), write_pos = 0;
    write_buf[write_pos++] = x;
}

template <class T>
inline void writeInt( T x, char end ) {
    if (x < 0)
        writeChar('-'), x = -x;

    char s[24];
    int n = 0;
    while (x || !n)
        s[n++] = '0' + x % 10, x /= 10;
    while (n--)
        writeChar(s[n]);
    if (end)
        writeChar(end);
}

inline void writeWord( const char *s ) {
    while (*s)
        writeChar(*s++);
}

struct Flusher {
    ~Flusher() {
        if (write_pos)
            fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;
    }
} flusher;
char s[64];
int main(void)
{
    int n,q;
    scanf("%d%d%s",&n,&q,str);
    const int N = 1 << n;
    for (int i = 0;i < N;++i)
    	str[i] -= '0';
    for (int i = 0;i < N;++i)
    	coef[i] = __builtin_popcount(i) & 1 ? -1 : 1;
    for (int i = 0;i < N;++i)
    	D0[i] = D1[i] = str[i];
    for (int i = 0;i < n;++i)
    	for (int mask = 0;mask < N;++mask)
    		if ((mask >> i) & 1)
    			D0[mask ^ (1 << i)] += D0[mask];
    		else
    			D1[mask ^ (1 << i)] += D1[mask];
   	while (q --) {
    	scanf("%s",s);
    	reverse(s,s + n);
    	int a = 0,b = 0,c = 0;
    	int la = 0,lb = 0,lc = 0;
    	for (int i = 0;i < n;++i) {
    		if (s[i] == '0')
    			a |= 1 << i,++la;
    		else
    		if (s[i] == '1')
    			b |= 1 << i,++lb;
    		else
    			c |= 1 << i,++lc;
    	}
    	int ans = 0;
    	if (la <= lb && la <= lc) {
    		for (int mask = a;mask >= 0;mask = !mask ? -1 : ((mask - 1) & a))
    			ans += coef[mask] * D0[(N - 1) ^ mask ^ c];
    	} else
    	if (lb <= la && lb <= lc) {
    		for (int mask = b;mask >= 0;mask = !mask ? -1 : ((mask - 1) & b))
    			ans += coef[mask] * D1[mask ^ c];
    	} else {
    		for (int mask = c;mask >= 0;mask = !mask ? -1 : ((mask - 1) & c))
    			ans += str[mask ^ b];
    	}
    	ans = abs(ans);
    	cout << ans << '\n';
    }
    return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:107:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for (int i = 0;i < n;++i)
     ^~~
snake_escaping.cpp:113:5: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
     while (q --) {
     ^~~~~
snake_escaping.cpp:99:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%s",&n,&q,str);
     ~~~~~^~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:114:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
      scanf("%s",s);
      ~~~~~^~~~~~~~

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