Codeforces Round #371 (Div. 2) C. Sonya and Queries

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;
}