Program to alphabetically sort names.

Program to alphabetically sort names. If you need help, comment below

#include<stdio.h>

#include<string.h>

void sort(int);

void disp(int);

struct student

       {char name[25];

       }a[50],*ptr;

int main()

       {ptr=a;

        int i,j,n;

        printf("\nEnter the number of students:");

        scanf("%d",&n);

        n++;

        printf("\nEnter the names:\n");

        for(i=0;i<n;i++)

               gets((ptr+i)->name);

        sort(n);

        disp(n);

        return 0;

       }

void sort(int n)

       {

        int i,j;

        char copy[25];

        for(i=0;i<n;i++)

               for(j=0;j<strlen((ptr+i)->name);j++)

                       {if((ptr+i)->name[j]<97)

                               (ptr+i)->name[j]+=32;

                       }

        for(i=0;i<n;i++)

               for(j=0;j<n-1;j++)

                       if(strcmp((ptr+j)->name,(ptr+j+1)->name)>0)

                               {strcpy(copy,(ptr+j)->name);

                                strcpy((ptr+j)->name,(ptr+j+1)->name);

                                strcpy((ptr+j+1)->name,copy);

                               }

       }

void disp(int n)

       {

        int i;

        for(i=0;i<n;i++)

               (ptr+i)->name[0]-=32;

        printf("\n\nThe sorted list is:\n");

        for(i=1;i<n;i++)

               puts((ptr+i)->name);

       }

Program for quick sort

Program to implement quick sort. If you need help, comment below

#include<stdio.h> int a[20],b[20],n,z; void quick(int x[],int first,int last) { int pivot; if(first<last) { pivot=partition(x,first,last); quick(x,first,pivot-1); quick(x,pivot+1,last); } } int partition(int x[],int first,int last) { int pivot,temp,i,j; pivot=first; i=first; j=last; while(i<j) { while((x[i]<=x[pivot])&&(i<last)) i++; while(x[j]>x[pivot]) j--; if(i<j) { temp=x[i]; x[i]=x[j]; x[j]=temp; } for(z=1;z<=n;z++) printf("%d\t ",a[z]); printf("\n"); } temp=x[pivot]; x[pivot]=x[j]; x[j]=temp; return j; } int main() { int i,j,c,ch; printf("\nQuicksort"); printf("\nEnter the no. of elements in the array:\t"); scanf("%d",&n); printf("\nEnter the elements into the array:\n"); for(i=1;i<=n;i++) scanf("%d",&a[i]); quick(a,1,n); printf("\nAfter sorting:\n"); for(i=1;i<=n;i++) printf("%d ",a[i]); }

Program for merge sort.

Program for merge sort. If you need help, feel free to ask.

#include<stdio.h> void mergesort(int x[20],int n) { int temp[20],i,j,k,l1,l2,size,u1,u2,a; size=1; while(size<n) { l1=0; k=0; while(l1+size<n) { l2=l1+size; u1=l2-1; u2=((l2+size-1<n)?l2+size-1:n-1); for(i=l1,j=l2;i<=u1&&j<=u2;k++) { if(x[i]<=x[j]) { temp[k]=x[i]; i++; } else { temp[k]=x[j]; j++; } } for(;i<=u1;k++) { temp[k]=x[i]; i++; } for(;j<=u2;k++) { temp[k]=x[j]; j++; } l1=u2+1; } for(i=l1;k<n;k++) temp[k++]=x[i]; for(i=0;i<n;i++) x[i]=temp[i]; size=size*2; printf("\n"); for(a=0;a<n;a++) printf("%d ",x[a]); printf("\n"); } } main() { int x[20],n,i; printf("\nEnter the value of the number of elements you wish to enter\n"); scanf("%d",&n); printf("\nEnter values of the elements you wish to sort"); for(i=0;i<n;i++) scanf("%d",&x[i]); printf("\nBefore Sorting this is how it looks\n:"); for(i=0;i<n;i++) printf(" %d",x[i]); mergesort(x,n); }

Program for heap sort

Program for Heap Sort. Kinda tricky program. If you need help, comment below

#include<stdio.h> int tree[20],n,ah[20],c=0; void build(int m,int item) { int ptr,par,f=0; m=m+1; ptr=m; while(ptr>1) { par=ptr/2; if(item<=tree[par]) { tree[ptr]=item; f=1; break; } tree[ptr]=tree[par]; ptr=par; } if(f==0) tree[1]=item; } void delheap(int k,int m) { int left,right,ptr,last,i; ah[k]=tree[1]; last=tree[m]; m=m-1; ptr=1; left=2; right=3; while(right<=m) { if((last>=tree[left])&&(last>=tree[right])) { tree[ptr]=last; return; } if(tree[right]<=tree[left]) { tree[ptr]=tree[left]; ptr=left; } else { tree[ptr]=tree[right]; ptr=right; } left=2*ptr; right=left+1; } if((left==m)&&(last<tree[left])) { tree[ptr]=tree[left]; ptr=left; } tree[ptr]=last; c++; printf("\n\nPass %d: ",c); for(i=1;i<=m;i++) printf("%d ",tree[i]); } main() { int i,j; printf("\nEnter total number of elements:"); scanf("%d",&n); printf("\nEnter elements to be inserted : "); for(i=1;i<=n;i++) scanf("%d",&tree[i]); for(i=1;i<n;i++) build(i,tree[i+1]); printf("\n\nHeap : "); for(i=1;i<=n;i++) printf("%d ",tree[i]); for(i=n,j=1;i>1;i--,j++) delheap(j,i); if(i==1) ah[n]=tree[1]; printf("\n\nHeap sort : "); for(i=1;i<=n;i++) printf("%d ",ah[i]); }