#include <stdio.h>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

void showMenu() {
	printf("\nHello A");
	printf("\nHello B");
	printf("\nHello C");
	printf("\nHello D");
	printf("\nHello E");
}

void tinhTong(int n) {
	int sum = 0, i;
	for(i=1;i<=n;i++) {
		sum += i;
	}
	printf("\nTong 1->%d: %d", n, sum);
}

//Lay ket qua tinh tong -> ket can lay => kieu int
int tinhTong2(int n) {
	int sum = 0, i;
	for(i=1;i<=n;i++) {
		sum += i;
	}
	printf("\nTong 1->%d: %d", n, sum);
	return sum;
}

void main(int argc, char *argv[]) {
	/*//Khai bao mang 3x5
	int t[3][5];
	//row: 3, column: 5
	//i: 0 => row - 1, j: 0 -> column
	//t[i][j] => t[0][0]
	t[1][2] = 16;
	printf("\nKet qua t[1][2] = ", t[1][2]);
	//Nhap tu ban phim
	printf("\nNhap t[2][2]: ");
	scanf("%d", &t[2][2]);
	//TH => nhap cho ca mang t.
	int i, j;//i => row, j => column
	for(i=0;i<3;i++) {
		for(j=0;j<5;j++) {
			printf("\nNhap t[%d][%d] = ", i, j);
			scanf("%d", &t[i][j]);
		}
	}*/
	showMenu();
	int i;
	printf("\nNhap i = ");
	scanf("%d", &i);
	printf("\n%d", i);
	
	showMenu();
	
	showMenu();
	
	int sum1 = 0;
	for(i=1;i<=10;i++) {
		sum1 += i;
	}
	printf("\nTong 1->10: %d", sum1);
	
	int sum2 = 0;
	for(i=1;i<=20;i++) {
		sum2 += i;
	}
	printf("\nTong 1->20: %d", sum2);
	
	if(sum1 >= sum2) {
		printf("\nTong 1-10 > 1-20");
	} else {
		printf("\nTong 1-10 < 1-20");
	}
	
	int sum = 0;
	for(i=1;i<=100;i++) {
		sum += i;
	}
	printf("\nTong 1->100: %d", sum);
	//su dung ham
	tinhTong(10);
	tinhTong(20);
	tinhTong(100);
	
	//So sanh tong 1->10, 1->20.
	int sum10 = tinhTong2(10);//sum10 = 55
	int sum20 = tinhTong2(20);//sum20 = ..
	
	if(sum10 >= sum20) {
		printf("\nTong sum10 >= sum20");
	} else {
		printf("\nTong sum10 < sum20");
	}
}