相乘兩個矩陣

Question

時獲得的地址作爲輸出

您好我有一個關於相乘兩個矩陣

這個問題是我寫的

#include <stdio.h> 

void getData(int matrix1[20][20], int matrix2[20][20], int row1, int row2, int col1, int col2); 
void matrixMult(int matrix1[20][20], int matrix2[20][20], int matrix3[20][20], int row1, int row2, int col1, int col2); 

int main(void) 
{ 
    // global declarations 
    int matrix1[20][20]; 
    int matrix2[20][20]; 
    int matrix3[20][20]; 
    int row1; 
    int row2; 
    int col1; 
    int col2; 


     printf("Enter first matrix dimension: "); 
     scanf("%d %d", &row1, &col1); 
     printf("%d x %d\n", row1, col1); 
     printf("Enter first matrix dimension: "); 
     scanf("%d %d", &row2, &col2);  
     printf("%d x %d\n", row2, col2); 
     printf("\n"); 

     if(col1 == row2) 
     { 
      getData(matrix1, matrix2, row1, row2, col1, col2); 
      matrixMult(matrix1, matrix2, matrix3, row1, row2, col1, col2); 
     } 




    return 0; 
} 

void getData(int matrix1[20][20], int matrix2[20][20], int row1, int row2, int col1, int col2) 
{ 
    // local declarations 
    int i = 0; 
    int j = 0; 

    printf("Enter number by row and column: "); 
    printf("\n"); 
    // input first matrix 
    for(i = 0; i < row1; i++) 
     for(j = 0; j < col1; j++) 
     { 

      scanf("%d", &matrix1[i][j]); 
     } 
    // reset i and j 
    i = 0; 
    j = 0; 

    printf("Enter number by row and column: "); 
    printf("\n"); 
    // intput second matrix 
    for(i = 0; i < row2; i++) 
     for(j = 0; j < col2; j++) 
     { 
      scanf("%d", &matrix1[i][j]); 
     } 


    return; 
} 


void matrixMult(int matrix1[20][20], int matrix2[20][20], int matrix3[20][20], int row1, int row2, int col1, int col2) 
{ 
    int i = 0; 
    int j = 0; 
    int k = 0; 
    int sum = 0; 
    for(i = 0; i < row1; i++) 
    { 
     for(j = 0; j < col2; j++) 
     { 
      for (k= 0; k < row2; k++) 
      { 
       sum += matrix1[i][k] * matrix2[k][j]; 
      } 

      matrix3[i][j] = sum; 
      sum = 0; // set sum to 0 
     } 
    } 
    //reset i and j 
    i = 0; 
    j = 0; 
    printf("product of matrix 1 and 2: "); 
    printf("\n"); 
    for(i = 0; i < row1; i++) 
    { 
     for(j = 0; j < col2; j++) 
     { 
      printf("%d\t", matrix3[i][j]); 
     } 
     printf("\n"); 
    } 

    return; 
} 

乘法，而不是它的打印輸出後不打印值的代碼出那些逝去矩陣1，矩陣和matrix3時有什麼不好的代碼，我是不是做錯事的matrixMult函數值

Enter first matrix dimension: 2 2 
2 x 2 
Enter first matrix dimension: 2 3 
2 x 3 

Enter number by row and column: 
1 2 
2 3 
Enter number by row and column: 
1 2 3 
1 2 4 
product of matrix 1 and 2: 
40829548  41222770  41615992 

40829548  41222770  41615992 

的地址？

提前致謝。

---

我重新寫了只有主要的代碼，但這次的產品矩陣的最後一列還打印出垃圾

#include <stdio.h> 



int main(void) 
{ 
    // global declarations 
    int matrix1[20][20]; 
    int matrix2[20][20]; 
    int matrix3[20][20]; 
    int row1; 
    int row2; 
    int col1; 
    int col2; 
    int i = 0; 
    int j = 0; 
    int k = 0; 
    int sum = 0; 

     printf("Enter first matrix dimension: "); 
     scanf("%d %d", &row1, &col1); 
     printf("%d x %d\n", row1, col1); 
     printf("Enter first matrix dimension: "); 
     scanf("%d %d", &row2, &col2);  
     printf("%d x %d\n", row2, col2); 
     printf("\n"); 

     if(col1 != row2) 
     { 
      printf("Matrices cannot be multiply!"); 
     } 

     else 
     { 
      printf("Enter first matrix: "); 
      printf("\n"); 
      for(i = 0; i < row1; i++) 
       for(j = 0; j < col1; j++) 
        scanf("%d", &matrix1[i][j]); 

      printf("Enter second matrix: "); 
      printf("\n"); 
      for(i = 0; i < row1; i++) 
       for(j = 0; j < col1; j++) 
        scanf("%d", &matrix2[i][j]); 

      for(i = 0; i < row1; i++) 
      { 
       for(j = 0; j < col2; j++) 
       { 
        for (k= 0; k < row2; k++) 
        { 
         sum += matrix1[i][k] * matrix2[k][j]; 
        } 

        matrix3[i][j] = sum; 
        sum = 0; // set sum to 0 
       } 
      } 

      printf("product of matrix 1 and 2: "); 
      printf("\n"); 
      for(i = 0; i < row1; i++) 
      { 
       for(j = 0; j < col2; j++) 
       { 
        printf("%d\t", matrix3[i][j]); 
       } 
       printf("\n"); 
      } 


     } 


    return 0; 
} 

這是我的輸出

Enter first matrix dimension: 2 2 
2 x 2 
Enter first matrix dimension: 2 3 
2 x 3 

Enter first matrix: 
1 2 
3 4 
Enter second matrix: 
2 1 4 
2 5 6 
product of matrix 1 and 2: 
10  5  1717986916 
22  11  -1717986924 

爲什麼最後一欄是否打印出垃圾？

Answer 1

在你的代碼的問題就出在這裏：

printf("Enter number by row and column: "); 
    printf("\n"); 
    // intput second matrix 
    for(i = 0; i < row2; i++) 
     for(j = 0; j < col2; j++) 
     { 
      scanf("%d", &matrix1[i][j]);// you were entering the values in matrix1 and leaving the matri2 blank so make it matrix2 instead. 
     } 

更改此：

scanf("%d", &matrix1[i][j]);

這樣：

scanf("%d", &matrix2[i][j]);

Answer 2

我不認爲你所看到的是地址：你的printf語句似乎是正確的。你必須檢查你填充矩陣的函數，錯誤可能在那裏。如果您在程序開始時重置目標矩陣，它可以提供幫助。

我也建議您在閱讀後輸入您的輸入矩陣。