zoukankan      html  css  js  c++  java
  • C. Obtain The String

    You are given two strings ss and tt consisting of lowercase Latin letters. Also you have a string zz which is initially empty. You want string zz to be equal to string tt. You can perform the following operation to achieve this: append any subsequence of ss at the end of string zz. A subsequence is a sequence that can be derived from the given sequence by deleting zero or more elements without changing the order of the remaining elements. For example, if z=acz=ac, s=abcdes=abcde, you may turn zz into following strings in one operation:

    1. z=acacez=acace (if we choose subsequence aceace);
    2. z=acbcdz=acbcd (if we choose subsequence bcdbcd);
    3. z=acbcez=acbce (if we choose subsequence bcebce).

    Note that after this operation string ss doesn't change.

    Calculate the minimum number of such operations to turn string zz into string tt.

    Input

    The first line contains the integer TT (1T1001≤T≤100) — the number of test cases.

    The first line of each testcase contains one string ss (1|s|1051≤|s|≤105) consisting of lowercase Latin letters.

    The second line of each testcase contains one string tt (1|t|1051≤|t|≤105) consisting of lowercase Latin letters.

    It is guaranteed that the total length of all strings ss and tt in the input does not exceed 21052⋅105.

    Output

    For each testcase, print one integer — the minimum number of operations to turn string zz into string tt. If it's impossible print 1−1.

    Example
    input
    Copy
    3
    aabce
    ace
    abacaba
    aax
    ty
    yyt
    
    output
    Copy
    1
    -1
    3
    #include <iostream>
    #include <vector>
    #include <algorithm>
    #include <string>
    #include <set>
    #include <queue>
    #include <map>
    #include <sstream>
    #include <cstdio>
    #include <cstring>
    #include <numeric>
    #include <cmath>
    #include <iomanip>
    #include <deque>
    #include <bitset>
    //#include <unordered_set>
    //#include <unordered_map>
    //#include <bits/stdc++.h>
    //#include <xfunctional>
    #define ll              long long
    #define PII             pair<int, int>
    #define rep(i,a,b)      for(int  i=a;i<=b;i++)
    #define dec(i,a,b)      for(int  i=a;i>=b;i--)
    #define pb              push_back
    #define mk              make_pair
    using namespace std;
    int dir1[6][2] = { { 0,1 } ,{ 0,-1 },{ 1,0 },{ -1,0 },{ 1,1 },{ -1,1 } };
    int dir2[6][2] = { { 0,1 } ,{ 0,-1 },{ 1,0 },{ -1,0 },{ 1,-1 },{ -1,-1 } };
    const long long INF = 0x7f7f7f7f7f7f7f7f;
    const int inf = 0x3f3f3f3f;
    const double pi = 3.14159265358979;
    const int mod = 100007;
    const int N = 1005;
    //if(x<0 || x>=r || y<0 || y>=c)
    
    inline ll read()
    {
        ll x = 0; bool f = true; char c = getchar();
        while (c < '0' || c > '9') { if (c == '-') f = false; c = getchar(); }
        while (c >= '0' && c <= '9') x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
        return f ? x : -x;
    }
    ll gcd(ll m, ll n)
    {
        return n == 0 ? m : gcd(n, m % n);
    }
    
    int main()
    {
        int T;
        cin >> T;
        while (T--)
        {
            string s, t;
            cin >> s >> t;
            vector<vector<int>> a(26);
            for (int i = 0; i < s.size(); i++)
            {
                a[(s[i] - 'a')].push_back(i);
            }
            int cant=0,res=1,last=-1;
            for (int i = 0; i < t.size(); i++)
            {
                if (a[t[i]-'a'].size() == 0)
                {
                    cant = 1;
                    break;
                }
                if (upper_bound(a[t[i] - 'a'].begin(), a[t[i] - 'a'].end(), last) == a[t[i] - 'a'].end())
                {
                    res++;
                    last = -1;
                    i--;
                }
                else
                {
                    last = *upper_bound(a[t[i] - 'a'].begin(), a[t[i] - 'a'].end(), last);
                }
            }
            if (cant)
                cout << -1 << endl;
            else
                cout << res << endl;
        }
        return 0;
    }
  • 相关阅读:
    【题解】 bzoj1191: [HNOI2006]超级英雄Hero (二分图)
    谈谈Android项目框架的前世今生
    十四个好用的开源漏洞检测工具
    关于Java导出100万行数据到Excel的优化方案
    逗号分割符--字段中含逗号等情况的解析方法Java实现
    Java日期处理
    服务器&浏览器伪装的故事
    浏览器User-agent简史(user-agent)
    修改tomcat服务器banner的方法
    life_motto
  • 原文地址:https://www.cnblogs.com/dealer/p/12778792.html
Copyright © 2011-2022 走看看