敏感词

题目链接： http://exercise.acmcoder.com/online/online_judge_ques?ques_id=3354&konwledgeId=40

解题思路： 题目没有给出字符串的范围，不过还是比较小的，直接暴力判断了。

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
const int MAXN=100005;
const LL MON7 = 1e9+7;
string s1[MAXN];
char s[MAXN];
int n;
bool mask[MAXN];

char lower(char ch)
{
    if (ch>='A' && ch<='Z') return ch-'A'+'a';
    return ch;
}

int main()
{
    // cout<<lower('G')<<endl;
#ifndef ONLINE_JUDGE
    freopen("test.txt","r",stdin);
#endif // ONLINE_JUDGE
    scanf("%d",&n);
    for (int i=1;i<=n;++i)
    {
        scanf("%s",s);
        for (int j=0;s[j];++j)
        {
            if (s[j]>='A' && s[j]<='Z') s[j]=s[j]-'A'+'a';
        }
        s1[i]=s;
        //cout<<s1[i]<<endl;
    }
    getchar();
    gets(s);getchar();
    //puts(s);
    int Len=strlen(s);
    memset(mask, 0, sizeof(mask));
    for (int i=0;i<Len;++i)
    {
        if (!isalpha(s[i])) continue;
        //printf("s=%s
",s+i);
        for (int j=1;j<=n;++j)
        {
            if (i+s1[j].length()>Len) continue;
            int flags=1;
            for (int k=0;k<s1[j].length();++k)
            {
                //if (s1[j]=="gre") printf("%c==%c
",s[i+k],lower(s1[j][k]));
                if (lower(s[i+k])!=s1[j][k]) {flags=0;break;}
            }
            //printf("s1[%d]=%s flags=%d
",j,s1[j].c_str(), flags);
            if (flags)
            {
                for (int k=0;k<s1[j].length();++k) mask[i+k]=1;
            }
        }
    }
    for (int i=0;i<Len;++i)
    {
        if (mask[i]) printf("*");
        else printf("%c",s[i]);
    }
    printf("
");
    return 0;
}