c++实现4阶矩阵或行列式的计算

           由于测试数目太少，会有各种bug，不一定每个矩阵都能计算出来，以后我会陆续优化，各位见谅

//mat.cpp  文件二
#include"mat.h"
#include
using namespace std;

//测试
void Mat::asd(){
	double a1[4][5] = { { 2, -1, -1, 1, 2 }, { 1, 1, -2, 1, 4 },//
	{ 4, -6, 2, -2, 4 }, { 3, 6, -9, 7, 9 } };//
	for (int i = 0; i < 4; i++){//
		for (int j = 0; j < 4; j++){
			Mat::mat[i][j]= a1[i][j];//测试，删掉
		}}}//删掉

//输入
void Mat::assignment() {
	for (int i = 0; i < 4; i++){
		for (int j = 0; j < 4; j++){
			cin >> mat[i][j];
		}
	}
}

//输出
void Mat::show(){
	for (int i = 0; i < 4; i++){
		for (int j = 0; j < 4; j++){
			cout << mat[i][j]<<" ";
		}
		cout << endl;
	}
}

//比较          i:max   j:small
int Mat::compare(int i,int j,int k){
	if (mat[i][k]>mat[j][k]){
		Mat::swap(i,j,k);
	}
	if (mat[i][k] == 0){
		Mat::swap1(i, j, k);
	}
	return 0;
}

//交换升序
int Mat::swap(int i, int j,int k){
	double save[5];
	for (k; k < 4; k++){
		save[k] = mat[i][k];
		mat[i][k] = mat[j][k];
		mat[j][k] = save[k]; 
	}
	return 0;
}
//降序
int Mat::swap1(int i, int j, int k){
	double save[5];
	for (k; k < 4; k++){
		save[k] = mat[j][k];
		mat[j][k] = mat[i][k];
		mat[i][k] = save[k];
	}
	return 0;
}

//化简             
int Mat::operation(int a, int b){
	if (mat[a][b] == 1){
		int i,j;
		i = a + 1,j=b;
		for (; i < 4; i++){
			for (; j < 4; j++){
				mat[i][j] = mat[i][j] - mat[i][b] * mat[a][j];
			}
			mat[i][b] = 0;//mat[i][b] - mat[i][b] * mat[a][b];
		}
	}
	else{
		int y, z;
		y = a + 1, z = b ;
		for (; y < 4; y++){
			while(mat[y][b]>=mat[a][b] && (mat[a][b]>0||(mat[y][b]<0&&mat[a][b]<0))){
				for (; z < 4; z++){
					mat[y][z] = mat[y][z] - mat[a][z];
				}
				z = b ;
			}
		}
	}
	return 0;
}

//判断0
int Mat::judge(int i,int j){
	if (i == 0){
		if (Mat::mat[i + 1][j] == 0 && Mat::mat[i + 2][j] == 0 && Mat::mat[i + 3][j] == 0){
			return 1;}
	
	}
	else if (i == 1){
		if (Mat::mat[i + 1][j] == 0 && Mat::mat[i + 2][j] == 0){
			return 1;}
	}
	else if(i==2){
		if (Mat::mat[i + 1][j]==0){
			return 1;}
	}
}

//检测负数，化为正数
void Mat::judgef(int i,int j){
	int a;
	a = j;
	for (; i < 4;i++){
	    if (Mat::mat[i][j] < 0){
			for (; j < 4;j++){
				Mat::mat[i][j] = -Mat::mat[i][j];
				if (mat[i][j] == 0){
					mat[i][j] = -mat[i][j];
				}
			}
			j = a;
		}
	}
}

//最后两行排序
void Mat::sort(){
	double a;
	if (mat[2][2] > mat[2][3]){
        for (int j = 2; j < 4; j++){
				a = mat[2][j];
				mat[2][j] = mat[3][j];
				mat[3][j] = a;
		}
	}
}

void Mat::opera(){
	int a,b;
	a = mat[3][2], b = mat[2][2];
	if (a%b== 0){
		mat[3][4] = mat[3][4] / mat[3][3];
		mat[3][3] = 1;
	}
	else if (b%a == 0){
		mat[3][3] = mat[3][3] / mat[3][4];
		mat[3][3] = 1;
	}
}

int Mat::zero(){
	if (mat[2][2] == 0 && mat[2][3] >= 0 && mat[3][2] > 0 && mat[3][3]){
		double b;
		b = mat[2][2];
		mat[3][2] = mat[2][2];
		mat[2][2] = b;
		b = mat[2][3];
		mat[3][3] = mat[2][3];
		mat[2][3] = b;
	}
	return 0;
}

//源.cpp  文件三
#include"mat.h"
#include
using namespace std;

int main(){
	int q = 0, w = 0,e,r;
	Mat a;
	cout << "Please enter 4*4 matix:" << endl;
	//a.asd();//测试，删掉
	a.assignment();                     //输入
	cout << endl;
	cout << "Enter matrix is";
	a.show();//
	cout << endl;
	do{
		for (int i = 0; i < 4; i++){      //冒泡排序
			for (int j = 3; j > i; j--){
				a.compare(i, j, 0);
			}
		}
		a.show();
		cout << endl;
		a.operation(q, w);                   //化简
		a.show();//
		cout <<"第一列 1"<e; j--){
				a.compare(e, j, 1);
			}
		}
		a.show();//
		cout <<"第二列  1"<< endl;
		a.operation(q, w);                 //化简
		a.show();//
		cout <<"第二列  2"<< endl;
		a.judgef(q,w);
		a.show();//
		cout << "第二列  3" << endl;
	} while (a.judge(q,w)!=1);
	q++, w++; //第二列结束  q=w=2 即3行

	do{
		e = q;     //保证q值不变
		for (e; e < 4; e++){                //排序
			for (int j = 3; j>e; j--){
				a.compare(e, j, 2);
			}
		}
		a.show();//
		cout << "第三列  1" << endl;
		a.operation(q, w);                 //化简
		a.show();//
		cout << "第三列  2" << endl;
		a.judgef(q,w);
		a.show();//
		cout << "第三列  3" << endl;
	} while (a.judge(q, w) != 1);
	//第三列结束
	 //q++, w++;   q=w=3
	
	//do{
		e = q;     //保证q值不变
			for (e; e < 4; e++){                //排序
				for (int j = 3; j>e; j--){
					a.compare(e, j, 2);
				}
		    }
		a.show();//
		cout << "第四列  1" << endl;
		a.operation(q, w);                 //化简
		a.show();//
		cout << "第四列  2" << endl;
		a.judgef(q,w);
		a.show();//
		cout << "第四列  3" << endl;
	//} while (a.judge(q, w) != 1);

	//a.sort(); a.show(); cout << endl;
	//a.operation(q, w);
    //a.judgef(q,w);
	/*q++; w++;
	a.opera();
	a.judgef(q, w);
	a.operation(q,w);*/
	a.zero();
	
	a.show();
	
	
	


	system("pause");
	return 0;
}

//mat.h  文件一
class Mat{
public:
	void asd();//测试
	void assignment();         //输入数组
	int compare(int,int,int);  //比较，找出1
	int swap(int,int,int);     //交换，最小值（1）到最上面
	int swap1(int, int, int);
	int operation(int,int);    //计算，缩小元素
	int judge(int,int);        //检测0
	void judgef(int,int);     //检测负数，化为正数
	void sort();  
	void opera();
	int zero();
	void show();               //显示
private:
	double mat[4][5] ;
};