题目链接

分析：01trie树，很容易就看出来了，也没什么好说的。WA了一发是因为没有看见如果数字位数大于01序列的时候01序列也要补全0。我没有晚上爬起来打，白天发现过的人极多。

/*****************************************************/

//#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <map>

#include <set>

#include <ctime>

#include <stack>

#include <queue>

#include <cmath>

#include <string>

#include <vector>

#include <cstdio>

#include <cctype>

#include <cstring>

#include <sstream>

#include <cstdlib>

#include <iostream>

#include <algorithm>

using namespace std;

#define   offcin        ios::sync_with_stdio(false)

#define   sigma_size    26

#define   lson          l,m,v<<1

#define   rson          m+1,r,v<<1|1

#define   slch          v<<1

#define   srch          v<<1|1

#define   sgetmid       int m = (l+r)>>1

#define   LL            long long

#define   ull           unsigned long long

#define   mem(x,v)      memset(x,v,sizeof(x))

#define   lowbit(x)     (x&-x)

#define   bits(a)       __builtin_popcount(a)

#define   mk            make_pair

#define   pb            push_back

#define   fi            first

#define   se            second

const int    INF    = 0x3f3f3f3f;

const LL     INFF   = 1e18;

const double pi     = acos(-1.0);

const double inf    = 1e18;

const double eps    = 1e-9;

const LL     mod    = 1e9+7;

const int    maxmat = 10;

const ull    BASE   = 31;

/*****************************************************/

const int maxn = 3e5 + 5;

int ch[maxn][2];

int sz = 1;

LL val[maxn];

void addnode(LL x) {

    LL base = 1;

    int u = 0;

    for (int i = 0; i < 18; i ++) {

        int c = (x / base) % 10;

        c %= 2;

        if (!ch[u][c]) {

            ch[u][c] = sz ++;

            mem(ch[sz], 0);

            val[sz] = 0;

        }

        u = ch[u][c];

        base *= 10LL;

    }

    val[u] ++;

}

void deletenode(LL x) {

    LL base = 1;

    int u = 0;

    for (int i = 0; i < 18; i ++) {

        int c = (x / base) % 10;

        c %= 2;

        u = ch[u][c];

        base *= 10LL;

    }

    val[u] --;

}

int searchnode(char *s) {

    int len = strlen(s);

    LL ans = 0;

    int u = 0, c;

    for (int i = 0; i < 18; i ++) {

        if (i < len) c = s[len - 1 - i] - '0';

        else c = 0;

        u = ch[u][c];

        ans += val[u];

    }

    return ans;

}

int main(int argc, char const *argv[]) {

    int N;

    cin>>N;

    char op[2];

    char s[20];

    LL x;

    for (int i = 0; i < N; i ++) {

        scanf("%s", op);

        if (op[0] == '+') {

            cin>>x;

            addnode(x);

        }

        else if (op[0] == '-') {

            cin>>x;

            deletenode(x);

        }

        else {

            scanf("%s", s);

            cout<<searchnode(s)<<endl;

        }

    }

    return 0;

}