I AM CS ENGINEER: 2014

Friday, 23 May 2014

Login process using PHP and MySQL

First we will create a simple Login form...........

database name : login
table name : members

code: main_login.php

<form name="form1" method="post" action="checklogin.php">
memeber login<br>

Usename<br>
<input name="myusername" type="text" id="myusernaame"><br>
password<br>
<input name="mypassword" type="text" id="mypassword"><br>

<input type="submit" name="Submit" value="Login">

</form>

code : checklogin.php

<?php
session_start();
$host="localhost";
$username="root";
$password="";
$db_name="login";
$tbl_name="members";

mysql_connect("$host","$username","$password") or die("cant connect");
mysql_select_db("$db_name") or die("cant connect");

$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];

$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

$count=mysql_num_rows($result);
if($count==1){
//$_SESSION['logged']=TRUE;
$_SESSION['login_user']=$myusername;
header("location:login_success.php");
}
else{
echo "wrong username or password";
}
?>

code : login_success.php

<?php
session_start();
if(!$_SESSION['logged']){
header("location:main_login.php");
exit;
}
echo 'welcome, '.$_SESSION['login_user'];
?>

<html>
<body>
Login Successful
</body>
</html>

Scroll function in HTML

/*Scroll FunctionIn HTML */

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Scroll to Bottom or Top - DevCurry.com</title>
<script type="text/javascript"
src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js">
</script>
<script type="text/javascript" language="javascript">
$(function () {
$('#scrlBotm').click(function () {
$('html, body').animate({
scrollTop: '1000px'
},
1500);
return false;
});
$('#scrlmid').click(function () {
$('html, body').animate({
scrollTop: $(document).height()
},
700);
return false;
});

$('#scrlTop').click(function () {
$('html, body').animate({
scrollTop: '0px'
},
1500);
return false;
});

});
</script>
</head>
<body>
<a id="scrlBotm" href="#">Scroll to mid</a>
<div style="height:1500px"></div>
<a id="scrlmid" href="#">Scroll to Bottom</a>
<div style="height:1000px"></div>
<a id="scrlTop" href="#">Scroll to Top</a>
</body>
</html>

Tuesday, 11 February 2014

some important printf syntax in C

#include<stdio.h>
//code by rajendra
main(){
    char str[30];
    int a=10,b=3;
float result;
result=((float)a)/b;
//result=(float)(a/b);
printf("%d\n",result);

    printf("jitendra"+2);//read after first two
    printf("\n%d %d");//garbage
    printf("\n%d\n",5,7);//output =5
    printf(3+"jitendra");//read after 3 char
    printf("\n");
    printf(3+"jitendra"+2);//read after first 2+3=5 character
    printf("\n");
    printf("%c\n","ABCDEF"[2]);//output C
    //scanf("%[^a]",str);//read the string till alphabate a
    //scanf("%[^\n]",str);//read till enter
    printf("%s",str);

    printf("percenatage symbol is %% char of the keyboard\n");//print % symbol
    printf("backslash is \\ character \n\n");
    printf("print double quota using \" and single is '\n\n");
}

C code of solving Quardratic equation

#include<stdio.h>
#include<math.h>
//code by rajendra
main(){
    int a,b,c,d;
    float root1,root2;
    printf("enter the coefficient of a,b,c \n");
    scanf("%d%d%d",&a,&b,&c);
    d=b*b-4*a*c;
    if(d>0){
        root1=(-b+sqrt(d))/(2*a);
        root2=(-b-sqrt(d))/(2*a);
        printf("first root is = %f and second root is = %f\n",root1,root2);
    }
    else
    printf("root are imaginory");
}

C header file 'stdlib' functions implementation

#include<stdio.h>
#include<stdlib.h>
//code by rajendra
main(){
   int ival,d_plc,sign;
   long lval;
   unsigned long ulval=362880L;
   float real1,real2=-57.12345;
   char str1[20]="-250",str2[20]="765.2345",str3[20],str4[33],*str5;
   ival=atoi(str1);
   lval=atol("12345678");
   real1=atof(str2);
   printf("%d %ld %.4f\n",ival,lval,real1);
   itoa(67,str3,8);
   ultoa(ulval,str4,2);
   printf("%s %s\n", str3,str4);
   str5=fcvt(real2,5,&d_plc,&sign);
   printf("%.5f conversion gives: String %s,Decimal is at place %d, Sign is %d",real2,str5,d_plc,sign);

}

C Code for easy matrix multiplication

#include<stdio.h>
//code by rajendra
    void readmat(int row,int col,int mat[][10]){
        int a,b;
        for(a=0;a<row;a++)
            for(b=0;b<col;b++)
                scanf("%d",&mat[a][b]);

    }
    void printmat(int row,int col,int mat[][10]){
        int a,b;
        for(a=0;a<row;a++)
            for(b=0;b<col;b++)
                scanf("%d",&mat[a][b]);
            printf("\n");

    }
    void multiply(int row1,int col1,int col2,int mat1[][10],int mat2[][10],int mat3[][10]){
        int a,b,c;
        for(a=0;a<row1;a++)
            for(b=0;b<col2;b++){
            int val=0;
                for(c=0;c<col1;c++)
                    val+=mat1[a][c]*mat2[c][b];
                    mat3[a][b]=val;


        }
    }
main(){
    int r1,c1,r2,c2,m1[10][10],m2[10][10],m3[10][10];
    printf("Enter the order of first matrix");
    scanf("%d%d",&r1,&c1);
    printf("the first matrix\n");
    readmat(r1,c1,m1);
    printf("Enter the order of second matrix");
    scanf("%d%d",&r2,&c2);
    printf("the first matrix\n");
    readmat(r2,c2,m2);

    if(c1!=r2)
        printf("multiplicatio is not allowed\n");
    else
        {
            printf("multiplication of two matrix is= \n");
            multiply(r1,c1,c2,m1,m2,m3);
            printmat(r1,c2,m3);
        }
    }

C code for execution time calculation

#include<stdio.h>
#include<time.h>
//code by rajendra
main(){
    long int a;
    int b=10;
    clock_t start, end;
    start=clock();
    for(a=0;a<=10000000L;a++){
        switch(b)
        {
            case 1:break;
            case 2:break;
            case 3:break;
            case 4:break;
            case 5:break;
            case 6:break;
            case 7:break;
            case 8:break;
            case 9:break;
            case 10:break;

            end=clock();
            printf("Time taken by switch statement between the two execution : %f\n",(end-start)/CLK_TCK);
}
    }
}

C Code for decimal and Octal numbers

#include<stdio.h>
//code by rajendra lora
main(){
    int x=075,y=0117,z=0x60;
    printf("x=%x y=%X z=%o\n",x,y,z);

}

Monday, 27 January 2014

Finding the factorial between 1 to 100 numbers

#include<stdio.h>

int main(){

    int t,i,j,temp,n,index;
    int arr[200];
    scanf("%d",&t);

    while(t>0){
    scanf("%d",&n);

    i=2;
    temp=0;
    arr[0]=1;
    index=1;

    while(i<=n)
    {
        for(j=0;j<index;j++)
        {
            arr[j]=arr[j]*i+temp;
            temp=arr[j]/10;
            arr[j]=arr[j]%10;
        }
    while(temp>0)
        {
            arr[index]=temp%10;
            temp=temp/10;
            index++;
        }
        i++;
    }
        for(i=index-1;i>=0;i--)
        {
            printf("%d",arr[i]);
        }
        printf("\n");
        t--;
    }
    return 0;
}

Sort the numbers in non-decreasing order (Turbo sort)

    #include <stdio.h>
    #define MAX 1000001
    int nums[MAX];

    int main(){
    int n;
    int x;
    for(x=0; x<MAX; x++)
    nums[x] = 0;
    scanf("%d", &n);
    while(n--){
    scanf("%d", &x);
    ++nums[x];
    }
    for(x=0; x<MAX; x++)
    while(nums[x]--)
    printf("%d\n", x);
    return 0;
}

Tuesday, 7 January 2014

Graph implementation as an Adjacency List in c

#include <stdio.h>
#include <stdlib.h>

// A structure to represent an adjacency list node
struct AdjListNode
{
    int dest;
    struct AdjListNode* next;
};

// A structure to represent an adjacency liat
struct AdjList
{
    struct AdjListNode *head; // pointer to head node of list
};

// A structure to represent a graph. A graph is an array of adjacency lists.
// Size of array will be V (number of vertices in graph)
struct Graph
{
    int V;
    struct AdjList* array;
};

// A utility function to create a new adjacency list node
struct AdjListNode* newAdjListNode(int dest)
{
    struct AdjListNode* newNode =
            (struct AdjListNode*) malloc(sizeof(struct AdjListNode));
    newNode->dest = dest;
    newNode->next = NULL;
    return newNode;
}

// A utility function that creates a graph of V vertices
struct Graph* createGraph(int V)
{
    struct Graph* graph = (struct Graph*) malloc(sizeof(struct Graph));
    graph->V = V;

    // Create an array of adjacency lists. Size of array will be V
    graph->array = (struct AdjList*) malloc(V * sizeof(struct AdjList));

     // Initialize each adjacency list as empty by making head as NULL
    int i;
    for (i = 0; i < V; ++i)
        graph->array[i].head = NULL;

    return graph;
}

// Adds an edge to an undirected graph
void addEdge(struct Graph* graph, int src, int dest)
{
    // Add an edge from src to dest. A new node is added to the adjacency
    // list of src. The node is added at the begining
    struct AdjListNode* newNode = newAdjListNode(dest);
    newNode->next = graph->array[src].head;
    graph->array[src].head = newNode;

    // Since graph is undirected, add an edge from dest to src also
    newNode = newAdjListNode(src);
    newNode->next = graph->array[dest].head;
    graph->array[dest].head = newNode;
}

// A utility function to print the adjacenncy list representation of graph
void printGraph(struct Graph* graph)
{
    int v;
    for (v = 0; v < graph->V; ++v)
    {
        struct AdjListNode* pCrawl = graph->array[v].head;
        printf("\n Adjacency list of vertex %d\n head ", v);
        while (pCrawl)
        {
            printf("-> %d", pCrawl->dest);
            pCrawl = pCrawl->next;
        }
        printf("\n");
    }
}

// Driver program to test above functions
int main()
{
    // create the graph given in above fugure
    int V = 5;
    struct Graph* graph = createGraph(V);
    addEdge(graph, 0, 1);
    addEdge(graph, 0, 4);
    addEdge(graph, 1, 2);
    addEdge(graph, 1, 3);
    addEdge(graph, 1, 4);
    addEdge(graph, 2, 3);
    addEdge(graph, 3, 4);

    // print the adjacency list representation of the above graph
    printGraph(graph);

    return 0;
}

Wednesday, 1 January 2014

Quick sort simple c code

#include<stdio.h>

void swap (int a[], int left, int right)
{
int temp;
temp=a[left];
a[left]=a[right];
a[right]=temp;
}//end swap

void quicksort( int a[], int low, int high )
{
int pivot;
// Termination condition!
if ( high > low )
{
pivot = partition( a, low, high );
quicksort( a, low, pivot-1 );
quicksort( a, pivot+1, high );
}
} //end quicksort

int partition( int a[], int low, int high )
{
int left, right;
int pivot_item;
int pivot = left = low;
pivot_item = a[low];
right = high;
while ( left < right )
{
// Move left while item < pivot
while( a[left] <= pivot_item )
   left++;
// Move right while item > pivot
while( a[right] > pivot_item )
   right--;
if ( left < right )
   swap(a,left,right);
}
// right is final position for the pivot
a[low] = a[right];
a[right] = pivot_item;
return right;
}//end partition

// void quicksort(int a[], int, int);
void printarray(int a[], int);

int main()
{
int a[50], i, n;
printf("\nEnter no. of elements: ");
scanf("%d", &n);
printf("\nEnter the elements: \n");
for (i=0; i<n; i++)
scanf ("%d", &a[i]);
printf("\nUnsorted elements: \n");
printarray(a,n);
quicksort(a,0,n-1);
printf("\nSorted elements: \n");
printarray(a,n);

}//end main

void printarray(int a[], int n)
{
int i;
for (i=0; i<n; i++)
printf(" %d ", a[i]);
printf("\n");
}//end printarray