Problem A. Lazy Spelling Bee Google APAC 2017 University Test Practice Round

这一题只要判断一下i,i-1,i+1位置处有多少个不同的字母就可以了。注意首尾两端要特判一下。

#include<iostream>#include<stdio.h>#include<cstdio>#include<stdlib.h>#include<vector>#include<string>#include<cstring>#include<cmath>#include<algorithm>#include<stack>#include<queue>#include<ctype.h>#include<map>#include<time.h>#include<set>#include<bitset>#include<sstream>using namespace std;//Google APAC2017 Practice Round Problem A. Lazy Spelling Beeconst long long mod=1e9+7;const int maxn=1010;//lead to WA it set it as 1000, since need end symbolint T;char w[maxn];long long ans;int combnum(int idx){    if(idx==0)    {        if(w[idx]==w[idx+1])        {            return 1;        }        else        {            return 2;        }    }    else if(idx==strlen(w)-1)    {        if(w[idx]==w[idx-1])        {            return 1;        }        else        {            return 2;        }    }    else    {        set<char>letter;        letter.clear();        letter.insert(w[idx-1]);        letter.insert(w[idx]);        letter.insert(w[idx+1]);        return letter.size();            }}int main(){    freopen("A-large-practice.in","r",stdin);    freopen("A-large-practice.out","w",stdout);    scanf("%d",&T);    for(int ca=1;ca<=T;ca++)    {        scanf("%s",w);        int len=strlen(w);        ans=1;        if(len==1)        {            ans=1;        }        else        {            for(int i=0;i<len;i++)            {//                ans=(ans%mod)*(combnum(i)%mod);                ans=ans*combnum(i);                ans%=mod;            }        }        printf("Case #%d: %lld\n",ca,ans);            }    return 0;}