warshall.cpp.bak

课程作业

#include < iostream >

using namespace std;

int main()
{
	int M[4][4];
	int a = 0;
	int b = 0;
	int c = 0;
	int d = 0;
	int test;


	while( a != 4 ){

		a = 0;
		cout<<"Enter the four elements on the first line of the matrix: "<<endl;

	    do{
			cin>>M[0][a];
		    test = M[0][a];
	    	a++;
		
		
		}while( a <=  3 && (test == 1 || test == 0 ) );
		
		if( a != 4 ){
			cout<<"Wrong number has been entered."<<endl;
		}

	}

	while( b != 4 ){

		b = 0;
		cout<<"Enter the four elements on the second line of the matrix: "<<endl;

	    do{
			cin>>M[1][b];
		    test = M[1][b];
	    	b++;
		
		}while( b <=  3 && (test == 1 || test == 0 ) );
		
		if( b != 4 ){
			cout<<"Wrong number has been entered."<<endl;
		}

	}

	while( c != 4 ){

		c = 0;
		cout<<"Enter the four elements on the third line of the matrix: "<<endl;

	    do{
			cin>>M[2][c];
		    test = M[2][c];
	    	c++;
		
		}while( c <=  3 && (test == 1 || test == 0 ) );
		
		if( c != 4 ){
			cout<<"Wrong number has been entered."<<endl;
		}

	}

	while( d != 4 ){
		
		d = 0;
		cout<<"Enter the four elements on the forth line of the matrix: "<<endl;

	    do{
			cin>>M[3][d];
		    test = M[3][d];
	    	d++;
		
		}while( d <=  3 && (test == 1 || test == 0 ) );
		
		if( d != 4 ){
			cout<<"Wrong number has been entered."<<endl;
		}



	}

	cout<<"The matrix entered is :"<<endl;
	
	for( int s = 0; s < 4; s++ ){
		for( int t = 0; t < 4; t++)
			cout<<"  "<<M[s][t];
		cout<<endl;
	}
	
	for(int k = 0; k < 4 ; k++){
		
		for(int i = 0; i < 4; i++ ){
			
			for(int j = 0; j < 4 ; j++){
				M[i][j]= ( ( M[i][j] + M[i][k] * M[k][j] ) >= 1 ? 1 : 0 );
				/*将所求路径分成两种情况，第一类是M( i , j )已经等于1，此时M( i , j )必等于1
				第二类是M( i , k ) = 1 并且M( k , j ) = 1 ,此时M( i , j )等于1
				且循环顺序不能乱*/
			
			}
		}
	}


	cout<<"The result is :"<<endl;
	for( int x = 0; x < 4; x++ ){
		for( int y = 0; y < 4; y++)
			cout<<"  "<<M[x][y];
		cout<<endl;
	}

	return 0;

}