Time Limit: 20 Sec
Memory Limit: 256 MB
http://codeforces.com/contest/549/problem/A
The developers of Looksery have to write an efficient algorithm that detects faces on a picture. Unfortunately, they are currently busy preparing a contest for you, so you will have to do it for them.
In this problem an image is a rectangular table that consists of lowercase Latin letters. A face on the image is a 2 × 2 square, such that from the four letters of this square you can make word "face".
You need to write a program that determines the number of faces on the image. The squares that correspond to the faces can overlap.
Input
Output
In the single line print the number of faces on the image
Sample Input
4 4
xxxx
xfax
xcex
xxxx
1
题意
给你n*m的格子,格子里面有字符串,然后问你有多少个2*2的格子里面,含有face
题解:
随便产生一组全排列,然后枚举就好了
代码:
//qscqesze #include <cstdio> #include <cmath> #include <cstring> #include <ctime> #include <iostream> #include <algorithm> #include <set> #include <vector> #include <sstream> #include <queue> #include <typeinfo> #include <fstream> #include <map> #include <stack> typedef long long ll; using namespace std; //freopen("D.in","r",stdin); //freopen("D.out","w",stdout); #define sspeed ios_base::sync_with_stdio(0);cin.tie(0) #define test freopen("test.txt","r",stdin) #define maxn 2000001 #define mod 10007 #define eps 1e-9 int Num; char CH[20]; const int inf=0x3f3f3f3f; const ll infll = 0x3f3f3f3f3f3f3f3fLL; inline ll read() { ll x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; } inline void P(int x) { Num=0;if(!x){putchar('0');puts("");return;} while(x>0)CH[++Num]=x%10,x/=10; while(Num)putchar(CH[Num--]+48); puts(""); } //************************************************************************************** string s[100]; string s1; int c[4]={0,1,2,3}; vector<int> a[50]; void unit() { int i = 0; do { for(int j = 0; j < 4; j++) a[i].push_back(c[j]); i++; } while(next_permutation(c,c + 4)); } int main() { //test; unit; int n=read(),m=read(); for(int i=0;i<n;i++) cin>>s[i]; s1="face"; int ans=0; int c[4]={0,1,2,3}; for(int i=0;i<n-1;i++) { for(int j=0;j<m-1;j++) { c[0]=0,c[1]=1,c[2]=2,c[3]=3; do{ if(s[i][j]==s1[c[0]]&&s[i+1][j]==s1[c[1]]&&s[i+1][j+1]==s1[c[2]]&&s[i][j+1]==s1[c[3]]) { ans++; break; } }while(next_permutation(c,c+4)); } } cout<<ans<<endl; }
The first line contains two space-separated integers, n and m (1 ≤ n, m ≤ 50) — the height and the width of the image, respectively.
Next n lines define the image. Each line contains m lowercase Latin letters.