Today’s Agenda

1. Today’s Agenda Recursion Array of Structures Introduction to Pointers

2. Recursion • Binary Search • Power Series • Maximum in an array • Factorial using accumulator method • Exercise • Minimum in an array

3. Binary Search int main() { int a[10] = {1,2,3,4,5,6,7,8,9,10}; int x=2; int index; index = bSearch(a,0,9,x); if(index == -1) printf("number not found\n"); else printf("number found at location %d\n",index); }

4. intbSearch(int a[],intlow,inthigh,int x) { intmid,index; mid = (low + high)/2; if(low>high) index = -1; else if(x > a[mid]) { low = mid+1; index = bSearch(a,low,high,x); } else if(x < a[mid]) { high = mid-1; index = bSearch(a,low,high,x); } else if(x == a[mid]) index = mid; return index; }

5. Power Series (1 + x^2 + x^3 + …+ x^n) int main() { int n=5,x=2; int sum; sum = recSum(x,n); printf("Sum = %d\n",sum); }

6. Power Series (1 + x^2 + x^3 + …+ x^n) int recSum(int x,int n) { int ans; if(n == 0) ans = 1; else ans = pow(x,n) + recSum(x,n-1); return ans; }

7. Maximum in an array int main() { int a[5] = {12,21,78,9,7}; int max; max = maxm(a,5); printf("max = %d\n",max); }

8. Maximum in an array intmaxm(int a[],int n) { int max; if(n == 1) max = a[n-1]; else { max = maxm(a,n-1); if(max < a[n-1]) max = a[n-1]; } return max; }

9. Factorial using accumulator method int main() { int n=5,acc=1,f; f = fact(n,acc); printf("%d! = %d\n",n,f); } int fact(intn,int acc) { if(n == 1) return (acc*1); else return fact(n-1,n*acc); }

10. Revisit Student Record typedefstruct { intidno; char name[20]; float marks[7]; discipline d; //declare enum for discipline float percent; grade g; //declare enum for grade }student; student s[10];

11. Operations: • void getStudent(student s[],int size); • void readMarks(student s); • void printStudent(student s[],int size); • void printMarks(student s); • float findPercent(student s[],int size); • grade findGrade(float percent);