two pointers

Given the sequence {1,2,3,4,5,6} and integer M = 8, there are examples of 2 + 6 = 8 and 3 + 5 = 8.

#include<cstdio>
const int maxn = 90;
int main(){
	int a[6]={1,2,3,4,5,6};
	
	int j=5,m=8,i=0;
	while(i<j){
		if(a[i]+a[j]==8){
			printf("%d %d\n",i,j);
			i++;
			j--;
		}else if(a[i]+a[j]<m) {
			i++;
		}else{
			j--;
		}
	}	
	return 0;
}

Merge two increasing sequences into one

#include<stdio.h>
const int maxn = 20;
int merge(int a[],int b[],int c[],int n,int m){
	int i=0,j=0,index=0;
	while(i<n&&j<m){
		if(a[i]<b[j]){
			c[index++]=a[i++];
		}else{
			c[index++]=b[j++];
		}	
	}
	while(i<n){
		c[index++]=a[i++];
	}
	
	while(j<m){
		c[index++]=a[j++];
	}	
	for(int i=0;i<m+n;i++){
		printf("%d ",c[i]);
	} 
}

int main(){
	int a[6]={2,4,7,8,9,10},b[6]={1,2,3,4,5,6},c[maxn];
	merge(a,b,c,6,6);	
}