109 lines
2.5 KiB
C++
109 lines
2.5 KiB
C++
/*
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Program: matrix-product-file-v1.c (Report comments/bugs to chikh@yuntech.edu.tw)
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Function: 從檔案讀入矩陣元素，並依所需維度配置記憶體空間、儲存矩陣內容，再進行乘法運算
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Notes:
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1) 輸入可為 matrixData1.txt、matrixData2.txt、matrixData3.txt 或 matrixData4.txt
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2) 動態配置二維陣列的方式可參見第四單元的複習：「C語言指標與字串」所載PPT檔案第64--68頁
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*/
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct {
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int row, col;
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int **data; /* 將用於表示二維陣列 */
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} matrix;
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int **readElements(FILE *filePtr, int row, int col)
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{
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int **data = (int**)malloc(row*sizeof(int*));
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int i, j, value;
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for (i = 0; i < row; i++) {
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data[i] = (int*)malloc(col*sizeof(int));
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for (j = 0; j < col; j++) {
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fscanf(filePtr," %d",&value);
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data[i][j] = value;
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}
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}
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return data;
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}
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int init(FILE *f, char *idA, matrix *A, char *idB, matrix *B) //初始化A與B矩陣
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{
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fscanf(f," %c %d %d %c %d %d",idA,&A->row,&A->col,idB,&B->row,&B->col);
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A->data = readElements(f,A->row,A->col);
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B->data = readElements(f,B->row,B->col);
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return 0;
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}
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int multiply(FILE *f, matrix *A, matrix *B, matrix *C)
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{
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int i, j, k, sum;
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if (A->col != B->row) {
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printf("矩陣維度不相符，無法運算！");
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return -1;
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}
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printf("乘積結果C_%dx%d\n",A->row,B->col);
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fprintf(f,"\n--- Output ---\nC_%dx%d\n",A->row,B->col);
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C->data = (int**)malloc(A->row*sizeof(int*));
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for (i = 0; i < A->row; i++) {
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C->data[i] = (int*)malloc(B->col*sizeof(int));
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for (j = 0; j < B->col; j++) {
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for (k = sum = 0; k < A->col; k++)
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sum += (A->data[i][k] * B->data[k][j]);
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C->data[i][j] = sum;
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printf("%d\t",C->data[i][j]);
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fprintf(f,"%d\t",C->data[i][j]);
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}
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printf("\n");
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fprintf(f,"\n");
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}
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C->row = A->row;
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C->col = B->col;
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return 0;
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}
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void show(char id, matrix *m)
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{
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int i, j;
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printf("%c_%dx%d = \n",id,m->row,m->col);
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for (i = 0; i < m->row; i++) {
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for (j = 0; j < m->col; j++)
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printf("%d\t",m->data[i][j]);
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printf("\n");
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}
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printf("\n");
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}
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int main()
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{
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char fileName[20], idA, idB;
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matrix A, B, C;
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FILE *f;
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printf("*** 矩陣相乘運算程式 ***\n\n輸入檔名 ==> ");
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scanf("%s",fileName);
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if ((f = fopen(fileName,"r+")) == NULL) {
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printf("\a%s檔案不存在！\n",fileName);
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return 1;
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}
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init(f,&idA,&A,&idB,&B);
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show(idA,&A);
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show(idB,&B);
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freopen(fileName,"a+",f); //重新開檔，將以附加(append)模式新增資料，避免檔案原有的資料被覆寫掉
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multiply(f,&A,&B,&C); //執行乘法運算過程中，將把結果顯示於螢幕並儲存於檔案中
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fclose(f);
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return 0;
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}
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