/************************************************************************
  功能:  本程序接受用戶輸入兩個(gè)矩陣,并作出計(jì)算選擇,返回計(jì)算值
 
**************************************************************************/
#include "iostream.h"
#include "iomanip.h"
#include "stdlib.h"
/****** 將m*N的矩陣C顯示出來 ******/
void Print(double *C, int m, int N) {
 for (int i = 0; i < m; i++) {
  for (int j = 0; j < N; j++) {
   cout<< setw(10) << C[i * N + j];
  }
  cout<< endl; //輸出一行后換行 
 }
}
/****** 將m*n的矩陣A與M*N的矩陣B相加,相加結(jié)果存到矩陣C中 ******/                      
void Madd(double *A, int m, int n, double *B, int M, int N, double *C) {
 if (m == M && n == N) { //判斷矩陣的行列是否滿足加法運(yùn)算
  for (int i = 0; i < m * n; i++) { 
   C[i] = A[i] + B[i];
  }
 } else {
  cout<< "您輸入的矩陣維數(shù)不符合做加法運(yùn)算!" << endl;
  exit(1); //退出
  
 }
}
/****** 將m*n的矩陣A與M*N的矩陣B相減,相加結(jié)果存到矩陣C中 ******/
void Msub(double *A, int m, int n, double *B, int M, int N, double *C) {
 if (m == M && n == N) { //判斷矩陣的行列是否滿足減法運(yùn)算
  for (int i = 0; i < m * n; i++) { 
   C[i] = A[i] - B[i];
  }
 } else {
  cout<< "您輸入的矩陣維數(shù)不符合做減法運(yùn)算!" << endl;
  exit(1); //退出
 }
}
/****** 將m*n的矩陣A與M*N的矩陣B相乘,相加結(jié)果存到矩陣C中 ******/
void Mmul(double *A, int m, int n, double *B, int M, int N, double *C) {
 if (n == M) { //判斷矩陣的行列是否滿足乘法運(yùn)算  
  for (int i = 0; i < m; i++) {
   for (int j = 0; j < N; j++) { 
    double temp = 0; //臨時(shí)變量存計(jì)算C[i][j]時(shí)產(chǎn)生的中間結(jié)果
    for (int k = 0; k < n; k++) {
     temp += A[i * n + k] * B[k * N + j];
    }
    C[i * N +j] = temp;
   }
  }
 } else {
  cout<< "您輸入的矩陣維數(shù)不符合做乘法運(yùn)算!" << endl; 
   exit(1);  //退出
 }
}
int main(void) { 
 int select, m, n, M, N; //select記錄用戶選擇運(yùn)算方式,m, n, M, N分別為A,B的行列數(shù)
 
 cout<< "請輸入A的行數(shù)列=";
 cin>> m;
 cout<< endl <<"請輸入A的列數(shù)=";
 cin>> n; 
 int An = m * n; //A的元素個(gè)數(shù)
 double *A;
 A = new double[An]; //為A動態(tài)分配一維數(shù)組空間
 cout<< "請按行輸入矩陣的元素:" << endl;
 for (int i = 0; i < An; i++) { //接受用戶輸入A的元素
  cin>> A[i];
 }
 
 cout<< "請輸入B的行數(shù)列=";
 cin>> M;
 cout<< endl <<"請輸入B的列數(shù)=";
 cin>> N;
 int Bn = M * N; //B的元素個(gè)數(shù)
 double *B;
 B = new double[Bn]; //為B動態(tài)分配一維數(shù)組空間
 cout<< "請按行輸入矩陣的元素:" << endl; 
 for (int j = 0; j < Bn; j++) { //接受用戶輸入B的元素
  cin>> B[j];
 }
 
 int Cn = m * N; //C的元素個(gè)數(shù)
 double *C; //為C動態(tài)分配一維數(shù)組空間
 C = new double[Cn];
 
 cout<< "請選擇矩陣運(yùn)算：[1]+ [2]- [3]*" <<endl; //根據(jù)用戶選擇的運(yùn)算調(diào)用相應(yīng)計(jì)算函數(shù) 
 cin>> select; //用戶輸入運(yùn)算選擇
 if (select == 1) Madd(A, m, n, B, M, N, C); 
 if (select == 2) Msub(A, m, n, B, M, N, C); 
 if (select == 3) Mmul(A, m, n, B, M, N, C);
 
 Print(C, m, N); //顯示計(jì)算結(jié)果
  
 delete []A; delete []B; delete []C; //釋放運(yùn)行中動態(tài)分配的數(shù)組空間
 
 return 0; 
}