tinhtong_dequy.cpp

#include<stdio.h>
#include<conio.h>
#include<string.h>

int tongN(int n);

int main() {
	int i, n, tinhtongN;
	
	printf("Nhap mot so nguyen duong: ");
	scanf("%d", &n);
    tinhtongN = tongN(n);
    printf("\nTong cac so tu 1 toi %d la: %d", n, tinhtongN);
    
    return (0);
    
}

int tongN(int n) {
	int tinhtong;
	if (n == 1) {
		return (1);
		
	} else {
		tinhtong= n + tongN(n - 1);
		
	}
	return (tinhtong);
}