resolved all problems

author- RIYA SINGHAL(1).c

@@ -1,14 +1,13 @@
-
 #include <stdio.h>
 int main()
 {
-    int x;
-    printf("enter the no. to be divided");
-    scanf("%d",x);
-    for(int i=0;i<=5;i+=1)
+    int x,i;
+    printf("enter the no. to be divided: ");
+    scanf("%d",&x);
+    for(i=1;i<=5;i+=1)
     {
-        int y=x/i;
-        printf("\n the quotient after dividing the given no. by %d is %d",i,y)
+        float y=(float)x/i;
+        printf("\n the quotient after dividing the given no. by %d is %.2f",i,y);
     }
     return 0;
-}
+}

author- RIYA SINGHAL(3).c

@@ -1,13 +1,12 @@
-
 #include <stdio.h>
 
 int main()
 {
-    int x=10;
-    for(int i=0;i<5;i-=1)
+    int x=10,i;
+    for(i=0;i<5;i+=1)
     {
         int x=9;
-        printf("the value of x variable is %d",x);
+        printf("the value of x variable is %d\n",x);
 
     }
     return 0;

author- RIYA SINGHAL(4).c

@@ -1,18 +1,17 @@
-
 #include <stdio.h>
 
 int main()
 {
-    int x=10;
-    for(int i=0;i<5;i-=1)//INFINITE LOOP
+    int x=10,i;
+    for(i=0;i<5;i+=1)
     {
         int x=9;
-        printf("the value of x variable is %d",x);
+        printf("the value of x variable is %d\n",x);
 
     }
-    char x;//ALREADY DECLARED ABOVE
-    printf("enter any character");
-    scanf("%c",&x);
-    printf("the entered character is %c",x);
+    char xy;
+    printf("enter any character: ");
+    scanf("%c",&xy);
+    printf("the entered character is %c",xy);
     return 0;
 }

author- RIYA SINGHAL(5).c

@@ -1,10 +1,9 @@
 #include <stdio.h>
-
 int main()
 {
-    int x=10;
-    for(int i=0;i<5;i-=1){
-        int x=9;
-    printf(x);}
+    int x=10,i;
+    for(i=0;i<5;i+=1){
+    x=9;
+    printf("%d",x);}
     return 0;
 }

author-AKSHITA(1).c

@@ -4,7 +4,7 @@ int main() {
     int n1, n2, i, flag;
     printf("Enter two positive integers: ");
     scanf("%d %d", &n1, &n2);
-    printf("Prime numbers between %d and %d are: ", n1, n2)
+    printf("Prime numbers between %d and %d are: ", n1, n2);
     for (i = n1 + 1; i < n2; ++i) {
 
         // flag will be equal to 1 if i is prime
@@ -18,11 +18,13 @@ int main() {
 // user-defined function to check prime number
 int checkPrimeNumber(int n) {
     int j, flag = 1;
+    if(n==1)
+     return 0;
     for (j = 2; j <= n / 2; ++j) {
         if (n % j == 0) {
             flag = 0;
             break;
         }
     }
     return flag;
-}
+}

author-AKSHITA(2).c

@@ -10,9 +10,11 @@ int main()
       remainder=temp%10;
       reverse_num=reverse_num*10+remainder;
       temp/=10;
+  }
    if(reverse_num==num) 
       printf("%d is a palindrome number",num);
    else
-      print("%d is not a palindrome number",num);
+      printf("%d is not a palindrome number",num);
+
    return 0;
-}
+}

author-ALI RAZA.c

@@ -1,14 +1,14 @@
-# include <stdio.h>
-void fun(int &x)
+#include<stdio.h>
+void fun(int* x)
 {
     *x = 30;
 }
 
 int main()
 {
   int y = 20;
-  fun(y);
-  printf("%d", *y);
+  fun(&y);
+  printf("%d", y);
   return 0;
 }
 

author-ALWINDER(1).c

@@ -2,13 +2,13 @@
 void fun(int *p) 
 { 
   int q = 10; 
-  p = &*&q; 
+  *p = &*&q; 
 }       
 int main() 
 { 
   int r = 20; 
-  int *p = &*r; 
+  int *p = &r; //p points to r
   fun(p); 
-  printf("%d", *&*&*p); 
+  printf("%d", *&*&*p); //p now points to address of q
   return 0; 
 }

author-ALWINDER(2).c

@@ -1,8 +1,9 @@
 #include<stdio.h>
 int main(){
  char *ptr = "void pointer";
- void *vptr;
+ int *vptr;
  vptr = &ptr;
- printf("%s" , **&(char **)vptr);
+ printf("%s" , **&vptr);
  return 0;
 }
+

author-CHANDAN(1).c

@@ -8,7 +8,7 @@ int main()
     scanf("%d",&a);
     printf("\nEnter value of b = ");
     scanf("%d",&b);
-    sum=a+bsub=a-b;
+    sum=a+b;sub=a-b;
     printf("\nSum: %d\nSub: %d",sum,sub);
     return 0;
 }

author-GURSANGAT(1).c

@@ -4,19 +4,22 @@ int main()
    int i = 0;
    for (i=0; i<20; i++)
    {
-     switch(i);
+     switch(i)
      {
        case 0:
          i += 5;
+         break;
        case 1:
          i += 2;
+         break;
        case 5:
          i += 5;
+         break;
        default:
          i += 4;
          break;
      }
-     printf("%c  "; i);
+     printf("%d ", i);
    }
    return 0;
-}
+}

author-GURSANGAT(2).c

@@ -1,11 +1,11 @@
-#include<stdi0.h>
+#include<stdio.h>
 
 int main()
 {
     char ch;
     int i;
-    scanf("%c", i);
-    scanf("%d", ch);
-    printf("%c %d", &ch, &i);
+    scanf("%c", &ch);
+    scanf("%d", &i);
+    printf("%c %d", ch, i);
     return 0;
 }

author-HIYA MADAN(1).c

@@ -11,14 +11,14 @@ void main()
 {
 char str[20];
 char *ptr=str,*temp;
-int i=0,j;
+int i=0,j,l;
 scanf("%[^\n]",str);
 while(*ptr)
 {
 i++;
 ptr++;
 }
-for(j=0;j
+for(j=0;j<i;j++)
 {
             if(*ptr==' ')
             {

author-HIYA MADAN(2).c

@@ -4,15 +4,16 @@
 void main()
 {
 
-    char *rev;
+    char rev[15];
     char str[15];
     scanf("%[^\n]",str);
     int i,j;
     for(i=strlen(str)-1,j=0;i>=0;i--,j++)
-      rev[j]=str[i];
+      {rev[j]=str[i];}
     rev[j]='\0';
     if(strcmp(rev,str))
       printf("\nThe string is not a palindrome");
     else
         printf("\nThe string is a palindrome");
+   getch();     
 }

author-JASKIRAT SINGH(1).c

@@ -1,8 +1,9 @@
 #include<stdio.h>
 
-void transpose(int arr[][],int n)
+void transpose(int arr[100][100],int n)
 {
 	int tra[n][n],i,j;
+
 	for(i=0;i<n;i++)
 	{
 		for(j=0;j<n;j++)
@@ -24,8 +25,8 @@ int main()
 	int n,i,j;
 	printf("Enter the order of matrix\n");
 	scanf("%d",&n);
-	int arr[n][n];
-	printf("Enter the elements");
+	int arr[100][100];
+	printf("Enter the elements:\n");
 	for(i=0;i<n;i++)
 	{
 		for(j=0;j<n;j++)
@@ -42,4 +43,5 @@ int main()
 		}
 		printf("\n");
 	}
+	return 0;
 }

author-JASKIRAT SINGH(2).c

@@ -1,11 +1,12 @@
 #include<stdio.h>
 int main()
 {
-	int i=0;
+	int i=1;
 	for(;i!=0&&i<2;i++) 	//no change should be made in conditions and content of loop!!
 	{
 		printf("division");
 	}
 	printf("%d",5/i);
 	return 0;
 }
+

author-PALAK AGRAWAL(1).c

@@ -1,14 +1,15 @@
 #include <stdio.h>
+int sum_arr(int arr[],int n);
 int main()
 {
-	int arr={23,45,132,90,345,1,45,8};
-	int sum=sum_arr(arr[],8);
-	printf("Sum=%d",sum);	
+	int arr[]={23,45,132,90,345,1,45,8};
+	int sum=sum_arr(arr,8);
+    printf("Sum=%d",sum);	
 	return 0;
 }
 int sum_arr(int arr[],int n)
 {
-	int sum;
+	int sum=0,i;
 	for(i=0;i<n;i++)
 	{
 		sum=sum+arr[i];

author-PALAK AGRAWAL(2).c

@@ -1,29 +1,34 @@
 #include <stdio.h>
 int isprime(int n)
 {
-	int i,f,c;
-	for(i=0;i<n;i++)
+	int i,f,c=0;
+	for(i=2;i<n;i++)
 	{
-		if(n%c==0)
-		c++;
+		if(n%i==0)
+		c++; 
 	}
-	if(c==2)
+	if(c==0)
 	{
 		f=1;
 	}
 	else 
 	{
 		f=0;
 	}
+	return f;
 }
 int main()
 {
 	int num;
 	printf("Enter a number:");
-	scanf("%d",num);
-	int r=isprime(num);
+	scanf("%d",&num);
+	if(num==1)
+	 printf("1 is neither prime nor composite");
+	else 
+	{int r=isprime(num);
 	if(r==1)
 	printf("%d is prime",num);
 	else
 	printf("%d is not prime",num);
+   }
 }

author-PRAGYA NAINWAL(1).c

@@ -1,4 +1,5 @@
 #include<stdio.h>
+char* ReverseOfString(char *str1);
 int main()
 {
     #define MAX 100
@@ -7,21 +8,21 @@ int main()
 	printf("------------------------------------------\n");	
 
     printf(" Input any string: ");
-    scanf("%s",&str1);
+    scanf("%s",str1);
 
     revstr = ReverseOfString(str1);//call the function ReverseOfString
 
     printf(" The reversed string is: %s\n\n",revstr);
     return 0;
 }
-char ReverseOfString(char str1[])
+char* ReverseOfString(char *str1)
 {
     static int i=0;
     static char revstr[MAX];
     if(*str1)
     {
          ReverseOfString(str1+1);//calling the function ReverseOfString itself
-         revstr[i=+1] = *str1;
+        revstr[i++] = *str1;
     }
     return revstr;
 }