Codeforces 914F. Substrings in a String(bitset)

  比赛的时候怎么没看这题啊...血亏T T

  对每种字符建一个bitset,修改直接改就好了,查询一个区间的时候对查询字符串的每种字符错位and一下,然后用biset的count就可以得到答案了。。。

#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<bitset>
#define ll long long
using namespace std;
const int maxn=100010, inf=1e9;
int n, ty, l, r, x;
bitset<maxn>v[26], ans;
char s[maxn], s2[maxn], c;
inline void read(int &k)
{
    int f=1; k=0; char c=getchar();
    while(c<'0' || c>'9') c=='-'&&(f=-1), c=getchar();
    while(c<='9' && c>='0') k=k*10+c-'0', c=getchar();
    k*=f;    
} 
int main()
{
    scanf("%s", s+1); int len=strlen(s+1);
    for(int i=1;i<=len;i++) v[s[i]-'a'][i]=1;
    read(n);
    for(int i=1;i<=n;i++)
    {
        read(ty);
        if(ty==1)
        {
            read(x); scanf("%c", &c);
            v[s[x]-'a'][x]=0;
            v[(s[x]=c)-'a'][x]=1;
        }
        else
        {
            read(l); read(r);
            scanf("%s", s2); int m=strlen(s2);
            if(r-l+1<m) {puts("0"); continue;}
            ans.set();
            for(int j=0;j<m;j++) ans&=(v[s2[j]-'a']>>j);
            printf("%d\n", (int)(ans>>(l)).count()-(int)(ans>>(r-m+2)).count());
        }
    }
}
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posted @ 2018-01-21 15:24  Sakits  阅读(596)  评论(0编辑  收藏