//判断矩阵中是否存在一条包含某字符串所有字符的路径,路径不能重复进入矩阵的格子 //回溯法+栈
//在第N个字符的周围格子没有找到第N+1个字符，这个时候要回退到第N-1个字符，重新设定第N个字符

#include <iostream>
#include<string.h>
#include<stdio.h>
using namespace std;
bool hasPathCore(char* matrix, int rows, int cols,int row,int col,char* str, int& pathLength, bool* visited);
bool hasPath(char* matrix, int rows, int cols, char* str){
    if(matrix==NULL || rows<1 || cols<1 ||str==NULL)
        return false;
    bool *visited=new bool[rows*cols];//标记这个格子是否走过
    memset(visited,0,rows*cols);

    int pathLength=0;
    for(int row=0;row<rows;++row){
        for(int col=0;col<cols;++col){
            if(hasPathCore(matrix,rows,cols,row,col,str,pathLength,visited))
                return true;
        }
    }
    delete[] visited;
    return false;
}
bool hasPathCore(char* matrix, int rows, int cols,int row,int col,char* str, int& pathLength, bool* visited){
    if(str[pathLength]=='\0')//初始
        return true;
    bool hasPath=false;

    if(row>=0 && row<rows && col>=0 && col<cols && matrix[row*cols+col]==str[pathLength] && !visited[row*cols+col]){//字符相等，没来过
        ++pathLength;
        visited[row*cols+col]=true;

        hasPath=hasPathCore(matrix,rows,cols,row,col-1,str,pathLength,visited)||//左
                hasPathCore(matrix,rows,cols,row-1,col,str,pathLength,visited)||//上
                hasPathCore(matrix,rows,cols,row,col+1,str,pathLength,visited)||//右
                hasPathCore(matrix,rows,cols,row+1,col,str,pathLength,visited);//下
        if(!hasPath){//这条路径不行

            --pathLength;
            visited[row*cols+col]=false;//回退到n-1
        }
    }
    return hasPath;
}

//**********************************test code*********************************
void Test(char* testName, char* matrix, int rows, int cols, char* str, bool expected)
{
    if(testName != NULL)
        printf("%s begins: ", testName);

    if(hasPath(matrix, rows, cols, str) == expected)
        printf("Passed.\n");
    else
        printf("FAILED.\n");
}

//ABCE
//SFCS
//ADEE

//ABCCED
void Test1()
{
    char matrix[] = "ABCESFCSADEE";
    char* str = "ABCCED";

    Test("Test1", (char*)matrix, 3, 4, str, true);
}

//ABCE
//SFCS
//ADEE

//SEE
void Test2()
{
    char matrix[] = "ABCESFCSADEE";
    char* str = "SEE";

    Test("Test2", (char*)matrix, 3, 4, str, true);
}

//ABCE
//SFCS
//ADEE

//ABCB
void Test3()
{
    char matrix[] = "ABCESFCSADEE";
    char* str = "ABCB";

    Test("Test3", (char*)matrix, 3, 4, str, false);
}

//ABCEHJIG
//SFCSLOPQ
//ADEEMNOE
//ADIDEJFM
//VCEIFGGS

//SLHECCEIDEJFGGFIE
void Test4()
{
    char matrix[] = "ABCEHJIGSFCSLOPQADEEMNOEADIDEJFMVCEIFGGS";
    char* str = "SLHECCEIDEJFGGFIE";

    Test("Test4", (char*)matrix, 5, 8, str, true);
}

//ABCEHJIG
//SFCSLOPQ
//ADEEMNOE
//ADIDEJFM
//VCEIFGGS

//SGGFIECVAASABCEHJIGQEM
void Test5()
{
    char matrix[] = "ABCEHJIGSFCSLOPQADEEMNOEADIDEJFMVCEIFGGS";
    char* str = "SGGFIECVAASABCEHJIGQEM";

    Test("Test5", (char*)matrix, 5, 8, str, true);
}

//ABCEHJIG
//SFCSLOPQ
//ADEEMNOE
//ADIDEJFM
//VCEIFGGS

//SGGFIECVAASABCEEJIGOEM
void Test6()
{
    char matrix[] = "ABCEHJIGSFCSLOPQADEEMNOEADIDEJFMVCEIFGGS";
    char* str = "SGGFIECVAASABCEEJIGOEM";

    Test("Test6", (char*)matrix, 5, 8, str, false);
}

//ABCEHJIG
//SFCSLOPQ
//ADEEMNOE
//ADIDEJFM
//VCEIFGGS

//SGGFIECVAASABCEHJIGQEMS
void Test7()
{
    char matrix[] = "ABCEHJIGSFCSLOPQADEEMNOEADIDEJFMVCEIFGGS";
    char* str = "SGGFIECVAASABCEHJIGQEMS";

    Test("Test7", (char*)matrix, 5, 8, str, false);
}

//AAAA
//AAAA
//AAAA

//AAAAAAAAAAAA
void Test8()
{
    char matrix[] = "AAAAAAAAAAAA";
    char* str = "AAAAAAAAAAAA";

    Test("Test8", (char*)matrix, 3, 4, str, true);
}

//AAAA
//AAAA
//AAAA

//AAAAAAAAAAAAA
void Test9()
{
    char matrix[] = "AAAAAAAAAAAA";
    char* str = "AAAAAAAAAAAAA";

    Test("Test9", (char*)matrix, 3, 4, str, false);
}

//A

//A
void Test10()
{
    char matrix[] = "A";
    char* str = "A";

    Test("Test10", (char*)matrix, 1, 1, str, true);
}

//A

//B
void Test11()
{
    char matrix[] = "A";
    char* str = "B";

    Test("Test11", (char*)matrix, 1, 1, str, false);
}

int main(int argc, char* argv[])
{
    Test1();
    Test2();
    Test3();
    Test4();
    Test5();
    Test6();
    Test7();
    Test8();
    Test9();
    Test10();
    Test11();

    return 0;
}