如何初始化二维数组更有效率?
给定一个数组arcs[n][n]
下面是我的代码
for(int i=0;i<n;i++)
for(int j=0;j<n;j++)
{
arcs[i][j]=arcs[j][i]=INF;
}
#include <stdio.h>
float data[500];
int i;
void main() {
for (i=0;i<500;i++) {data[i]=1.0f;printf("%g\n",data[i]);}
__asm {
push ecx
push edi
mov ecx,500
mov eax,0xBF800000 //-1.0f
lea edi,data
rep stosd
pop edi
pop ecx
}
for (i=0;i<500;i++) printf("%g\n",data[i]);
}
memset(arcs, 0, sizeof(arcs));
#include <stdio.h>
#include <float.h>
#define n 3
float data[n][n],f;
int y,x;
int main() {
for (y=0;y<n;y++) {
for (x=0;x<n;x++) {
data[y][x]=1.0f;printf("%g ",data[y][x]);
}
printf("\n");
}
f=FLT_MAX;
__asm {
push ecx
push edi
mov ecx,n*n
mov eax,f
lea edi,data
rep stosd
pop edi
pop ecx
}
for (y=0;y<n;y++) {
for (x=0;x<n;x++) {
printf("%g ",data[y][x]);
}
printf("\n");
}
return 0;
}
//1 1 1
//1 1 1
//1 1 1
//3.40282e+038 3.40282e+038 3.40282e+038
//3.40282e+038 3.40282e+038 3.40282e+038
//3.40282e+038 3.40282e+038 3.40282e+038
//
