int myarray[3][3]={
{0,0,0},
{0,0,1},
{0,0,0}};
int x=1;
int y=1;
int first=myarray[y][x];
int second=myarray[y][x+1];
int temp=second;
myarray[y][x+1]=first;
myarray[y][x]=temp;
Swapping values
June 08, 2002 04:43 PM
324
June 08, 2002 05:49 PM
It is hard to make it simpler than this:
void swap(int* a, int* b){ int temp = *a; *a = *b; *b = temp;}swap(&myarray[y][x+1], &myarray[y][x]);
Arguing on the internet is like running in the Special Olympics: Even if you win, you're still retarded.[How To Ask Questions|STL Programmer's Guide|Bjarne FAQ|C++ FAQ Lite|C++ Reference|MSDN]
1,658
June 08, 2002 05:59 PM
You don''t even have to implement it, just use std::swap in <algorithm>
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"Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." — Brian W. Kernighan
June 08, 2002 06:14 PM
Ok... thanks. Btw my friend asked me an interesting question today about arrays, and it got me wondering... Is it possible to just swap entire rows/columns with each other in an array?
122
June 08, 2002 06:53 PM
quote: Original post by Zorbfish
Ok... thanks. Btw my friend asked me an interesting question today about arrays, and it got me wondering... Is it possible to just swap entire rows/columns with each other in an array?
Lets say you have an array like this:
int Array[3][3];
So a row is 3 cells, maby a temp array would solve the problem:
int Array[3][3];
int tmpArray[3][1];
This code is not compiled, but I think should work fine
void Flip(int *Array, int Cols, int rowIndex1, int rowIndex2) { int tmpArray[3][1]; int i; for(i=0; i<Cols; i++) { tmpArray[i][0] = (rowIndex1 + (rowIndex1 * Cols)) + i; } // Put first row in tmpArray for(i=0; i<Cols; i++) { (rowIndex1 + (rowIndex1 * Cols)) = (rowIndex2 + (rowIndex2 * Cols)) } // Put second row in first row for(i=0; i<Cols; i++) { (rowIndex2 + (rowIndex2 * Cols)) = tmpArray[i][rowIndex1] } // Put tmp row in second row} Use it like:
int arrayX = 3, arrayY = 3;
int Array[arrayX][arrayY];
Flip(&Array[0][0], arrayY, 1, 3); // Flip row 1 and 3 in Array. It haves arrayY cols
First time I use pointers, I didn't know they were SO flexible
[edited by - the Chef on June 8, 2002 8:00:44 PM]
[edited by - the Chef on June 9, 2002 5:44:25 AM]
No way! I will never write a profile signature! :p
138
June 10, 2002 07:06 PM
/*How to swap two integers in just one line*/a^=b^=a^=b; It''s cool, isn''t it?
theNestruo
Syntax error in 2410
Ok
theNestruoSyntax error in 2410Ok
122
June 10, 2002 07:12 PM
Use VB, it''s like this
myArray(2,5) = myArray(4,3)
I win, you lose. J/K
Horny Farmer (Jolly Rancher)
myArray(2,5) = myArray(4,3)
I win, you lose.
J/K Horny Farmer (Jolly Rancher)
119
June 10, 2002 07:25 PM
quote: Original post by theNestruo
/*How to swap two integers in just one line*/
a^=b^=a^=b;
It''s cool, isn''t it?
That is pretty C
L, what exactly is going on there??bangz.
1,658
June 10, 2002 07:56 PM
In binary (^ is the XOR exclusive-or operation)
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a = 00001111 b = 00111100a^=b a = 00110011 b = 00111100b^=a a = 00110011 b = 00001111a^=b a = 00111100 b = 00001111 Documents [ GDNet | MSDN | STL | OpenGL | Formats | RTFM | Asking Smart Questions ]
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"Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." — Brian W. Kernighan
122
June 10, 2002 09:00 PM
Check this out:
a += b; // a + b
b = -b;
b += a; // (a + b) - b = a
a -= b; // (a + b) - a = b
But I think assembly beats both of them:
xchg a, b
Give a man a fish and you feed him for a day; teach him to use the Net and he won't bother you for weeks.
[edited by - thooot on June 10, 2002 10:01:36 PM]
a += b; // a + b
b = -b;
b += a; // (a + b) - b = a
a -= b; // (a + b) - a = b
But I think assembly beats both of them:
xchg a, b
Give a man a fish and you feed him for a day; teach him to use the Net and he won't bother you for weeks.
[edited by - thooot on June 10, 2002 10:01:36 PM]
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