What kind of Hash function is this? and what does it do?
hash[i] = 999999999;
sort(adj[i].begin(), adj[i].end());
for(int j = 0;j < adj[i].size();j++)
{
hash[i] += (hash[i]*hash[adj[i][j]])%mod;
hash[i] %= mod;
}
Related
#include <stdio.h>
int main(){
char a[5];
for(char i = 0, i < 5, ++i){
scanf("%c", &a[i]);
}
printf("%c", a[5]);
return 0;
}
I changed a[5] into a[i] in the printf, nothing changed.
I have compared with this one i found on the net(which works ofc):
int main() {
int values[5];
for(int i = 0; i < 5; ++i) {
scanf("%d", &values[i]);
}
for(int i = 0; i < 5; ++i) {
printf("%d\n", values[i]);
}
return 0;
}
You are using , instead of semi colon ; in the for loop.
for(char i = 0, i < 5, ++i)
Correct Usage:
for(char i = 0; i < 5; ++i)
I want to print that in the console:
*
**
***
**
*
so, my code is:
Scanner input = new Scanner(System.in);
int n = input.nextInt();
char c = '*';
if (1 < n && n < 20) {
for (int row = 1; row <= n; row++) {
for (int col = 1; col <= row; col++) {
System.out.print(c);
}
System.out.println();
}
any proposals how to finish?
You want to print "* **". Write this:
System.out.print("* **");
If my answer is not that what you excpected, than give us more information. What is your actual problem. See StackOverflowFAQ
If n is your "*" length,below code:
if (1 < n && n < 20) {
for (int row = 1; row <= n; row++) {
for (int col = 1; col <= row; col++) {
System.out.print(c);
}
System.out.println();
}
for (int row =1; row <= n; row++) {
for (int col = n-row; col >0 ; col--) {
System.out.print(c);
}
System.out.println();
}
}
On coffeescript loop 'for'
eg.
if 1 < x, code like below:
console.debug i for i in [1..0]
Generated code is:
var i;
for (i = 1; i >= 0; i--) {
console.debug(i);
}
if 1 > x,code like below:
console.debug i for i in [1..2]
Generated code is:
var i;
for (i = 1; i <= 2; i++) {
console.debug(i);
}
If i want write that javascript.How to ?
for(var i=1;i<=0;i++){
console.debug(i);
}
Because i don't know the condition is greater than left side or less than left side.
But i just want it i++
What's wrong with me?
EDIT BELOW:
For coffeescript's feature,I add condition before the loop or add condition on for loop.
eg:
if x - y >=1
console.debug i for i in [1..x-y]
or
console.debug i for i in [1..x-y] and x-y >=1
That's my way.Some one have good advice?
It looks like you want to do this:
console.debug i for i in [1..x-y] by 1
Which gets compiled to:
var i, _i, _ref;
for (i = _i = 1, _ref = x - y; _i <= _ref; i = _i += 1) {
console.debug(i);
}
for(var i=1;i<=0;i++){
console.debug(i);
}
is equivalent to
var i = 1;
while(true) {
console.debug(i);
i++;
}
which in coffeescript is written as
i = 1
while true
console.debug(i);
i++;
I am taking about 50 times as long as expected to loop through a simple assignment. My first reaction was that I had disordered my memory access in the arrays, resulting in cache misses. This doesn't seem the case, however.
The pixel value assignment and updating the arrays takes a dogs age. Do any one of you folks have an inclining as to why this is happening? (I am compiling for an iPod with an A4)
memset(columnSumsCurrentFrameA, 0, sizeof(unsigned int) * (_validImageWidth/numSubdivisions) );
memset(rowSumsCurrentFrameA, 0, sizeof(unsigned int) * (_validImageHeight/numSubdivisions) );
int pixelValue = 0;
int startingRow = 0;
int startingColumn = 0;
for (int i = 0; i < _validImageHeight/numSubdivisions; i++)
{
int index = (i + startingRow) * _imageWidth;
for( int j = 0; j < (_validImageWidth/numSubdivisions); j++)
{
pixelValue = imageData[index + startingColumn + j];
columnSumsCurrentFrameA[j] += pixelValue;
rowSumsCurrentFrameA[i] += pixelValue;
}
}
The result of _validImageWidth/numSubdivisions must be an integer, are you sure that is always the case?
Also, you should calculate _validImageWidth/numSubdivisions before entering the double loops, it's not safe to assume your compiler takes care of it.
int limit = _validImageHeight/numSubdivisions;
for (int i = 0; i < limit; i++)
{
int index = (i + startingRow) * _imageWidth;
for( int j = 0; j < limit; j++)
{
pixelValue = imageData[index + startingColumn + j];
columnSumsCurrentFrameA[j] += pixelValue;
rowSumsCurrentFrameA[i] += pixelValue;
}
}
I am having problems with bottoms-up mergesort. I have problems sorting/merging. Current code includes:
public void mergeSort(long[] a, int len) {
long[] temp = new long[a.length];
int length = 1;
while (length < len) {
mergepass(a, temp, length, len);
length *= 2;
}
}
public void mergepass(long[] a, long[] temp, int blocksize, int len) {
int k = 0;
int i = 1;
while(i <= (len/blocksize)){
if(blocksize == 1){break;}
int min = a.length;
for(int j = 0; j < blocksize; j++){
if(a[i*j] < min){
temp[k++] = a[i*j];
count++;
}
else{
temp[k++] = a[(i*j)+1];
count++;
}
}
for(int n = 0; n < this.a.length; n++){
a[n] = temp[n];
}
}
}
Obvious problems:
i is never incremented.
At no point do you compare two elements in the array. (Is that what if(a[i*j] < min) is supposed to be doing? I can't tell.)
Why are you multiplying i and j?
What's this.a.length?
Style problems:
mergeSort() takes len as an argument, even though arrays have an implicit length. To make matters worse, the function also uses a.length and length.
Generally poor variable names.
Nitpicks:
If you're going to make a second array of the same size, it is common to make one the "source" and the other the "destination" and swap them between passes, instead of sorting into a temporary array and copying them back again.