A3

binary search.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+
+int binary_search(int a[],int l,int u,int choice)//assumes array is sorted 
+{
+	int m;
+	while(l<u)
+	{
+		m=(l+u)/2;
+
+		if(a[m]==choice)
+			return m;
+
+		if(choice<a[m])
+			u=m-1;
+		else
+			l=m+1;
+	}
+
+	if(a[l]==choice)
+		return l;
+	else
+		return -1;
+}
+
+int main()
+ {
+ 	int a[10]={1,2,2,3,4,5,6,7,8,9};
+
+ 	int c=binary_search(a,0,9,2);
+ 	if(c==-1)
+ 		printf("NON existing\n");
+ 	else
+ 		printf("EXISTING at index %d\n",c);
+
+ 	return 0;
+ }

d_discrete.c

@@ -0,0 +1,28 @@
+	#include<stdio.h>
+
+	int main()
+	{
+		unsigned long long p,test,x,y,m,n;
+
+		scanf("%llu",&test);
+
+		for(;test>0;test--)
+		{
+			scanf("%llu%llu%llu",&x,&y,&m);
+
+			x%=m;
+
+			p=1;
+
+		for(;y>0;y/=2)
+		{
+			if(y & 1)
+				p=(p*x)%m;
+
+			x=(x*x)%m;
+		}
+			printf("%llu ",p);
+		}
+
+		return 0;
+	}

e.c

@@ -0,0 +1,43 @@
+#include<stdio.h>
+#include<stdlib.h>
+int a[1001];
+int b[1001];
+
+int main()
+{
+	int n,x,count=0,i,t;
+	scanf("%d%d",&n,&x);
+
+	for(i=0;i<n;i++)
+	{
+		scanf("%d",&t);
+		if(t<0)
+		{
+			t*=(-1);
+			a[t]++;
+		}
+		else if (t>0)
+		{
+			/* code */
+			b[t]++;
+		}
+	}
+
+	for(i=1;i<=x;i++)
+	{
+		if(a[i]==b[i])
+			continue;
+		else
+		{
+			t=abs(a[i]-b[i]);
+			if(t<0)
+				t*=(-1);
+			count+=t;
+			//count+=abs(a[i]-b[i]);
+		}
+	}
+
+	printf("%d",count);
+
+	return 0;
+}

h_merge.c

@@ -0,0 +1,89 @@
+#include<stdio.h>
+unsigned long long a[10000001];
+
+void merge(unsigned long long a[],unsigned long long l,unsigned long long m,unsigned long long u)
+{
+	unsigned long long i,j,n1,n2,k;
+
+    n1=m-l+1;
+	n2=u-m;
+
+    unsigned long long a1[n1],a2[n2];
+
+	for(i=0;i<n1;i++)
+		a1[i]=a[l+i];
+
+	for(i=0;i<n2;i++)
+		a2[i]=a[m+i+1];
+
+	i=j=0;
+
+    k=l;
+
+	while (i < n1 && j < n2)
+    {
+        if (a1[i] <= a2[j])
+        {
+            a[k] = a1[i];
+            i++;
+        }
+        else
+        {
+            a[k] = a2[j];
+            j++;
+        }
+
+        k++;
+    }
+
+    while (i < n1)
+    {
+        a[k] = a1[i];
+        i++;
+        k++;
+    }
+
+    while (j < n2)
+    {
+        a[k] = a2[j];
+        j++;
+        k++;
+    }
+
+}
+
+void merge_sort(unsigned long long a[],unsigned long long l,unsigned long long u)
+{
+	unsigned long long m;
+	if(l<u)
+	{
+		m=l+(u-l)/2;
+
+		merge_sort(a,l,m);
+		merge_sort(a,(m+1),u);
+        merge(a,l,m,u);
+
+	}
+
+}
+
+int main()
+{
+	unsigned long long n,k,i,j;
+
+	scanf("%llu%llu",&n,&k);
+	for(i=0;i<=n;i++)
+		scanf("%llu",&a[i]);
+
+	for(;i<10000001;i++)
+		a[i]=0;
+
+	merge_sort(a,0,n);
+
+	for(i=0;a[i]==0;i++);
+
+	for(;a[i]==a[i+1];i+=k);
+
+	printf("%llu\n",a[i]);
+	return 0;
+}