[問題] 二維陣列相乘

看板C_and_CPP作者lovelu8888 (華小穎)時間14年前 (2011/10/03 21:37)推噓0(0推 0噓 6→)

留言6則, 3人參與討論串4/5 (看更多)

不好意思我是新手 @@ 先附上我的程式碼就是八乘八的矩陣 #include <stdio.h> int i,j,k; int main(void) { float a[8][8]={3./4.,0,0,0,0,0,0,0, 0,(-3./4.),1./2.,0,1./2.,0,0,0, 0,1./2.,-3./4.,0,1./2.,0,0,0, 0,0,0,3./4.,0,1./2.,1./2.,0, 0,1./2.,1./2.,0,3./4.,0,0,0, 0,0,0,1./2.,0,(-3./4.),1./2.,0, 0,0,0,1./2.,0,1./2.,-3./4.,0, 0,0,0,0,0,0,0,3./4. }; float b[8][8]={1.,1.,1.,1.,1.,1.,1.,1., 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,}; float c[8][8]={0}; for(i=0;i<8;i++) for(j=0;j<8;j++) { printf("a%d%d=%.2f\n" ,i+1,j+1,a[i][j]); }; for(i=0;i<8;i++) for(j=0;j<8;j++) { printf(" b%d%d= %f \n",i+1,j+1,b[i][j]); }; for (i=0; i<8; i++) { for (j=0; j<8; j++) { for(k = 1; k<8; k++) { c[i][j] = c[i][j] +a[i][k] * b[k][j]; } printf("%f ", c[i][j]); } printf("\n"); } return 0; } ~ 為啥我的c陣列跑出都是0，@@ 還有在C裡面可以二維陣列乘一維陣列嗎? ex (8*8)*(8*1)=(8*1) 我剛剛自己試了好像是不行所以八乘一的矩陣就只能乖乖寫成八乘八的矩陣嗎? 感謝不好意思是我擺錯了我的b[8][8]={1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 1.,0,0,0,0,0,0,0, 我大概知道意思了那請問如何讓一維陣列讓c語言認為是直行而不是一列的呢?? -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.128.128.198

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