编程day3

1.在屏幕上输出以下图案：
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#include<stdint.h>
#include<stdlib.h>

int main1(){
int i = 0;
int j = 0;
int m = 0;
int n = 0;
for (i = 1; i <= 13; i=i+2){
for (j = 1; j <= i; j++){
printf("");
}
printf("\n");
}
for (m = 11; m >= 1; m = m - 2){
for (n = 1; n <= m;n++){
printf("");
}
printf("\n");
}
system(“pause”);
return 0;
}

2.求出0～999之间的所有“水仙花数”并输出。
“水仙花数”是指一个三位数，其各位数字的立方和确好等于该数本身，如；153＝1＋5＋3?，则153是一个“水仙花数”。
#include<stdio.h>
#include<stdlib.h>

int main2(){
int i;
int x, y, z;
for (i = 100; i <= 999; i++){
x = i % 10; //个位
y = i / 10 % 10; //十位
z = i / 100; //百位
if( i == xxx + yyy + zzz){
printf(" %d", i);
}
}
system(“pause”);
return 0;
}

求Sn=a+aa+aaa+aaaa+aaaaa的前5项之和，其中a是一个数字，
例如：2+22+222+2222+22222

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
int main(){
int a;
int Sn = 0;
printf(“please input a number: \n”);
scanf("%d", &a);
Sn = a * 5 + a * 4 * 10 + a * 3 * 100 + a * 2 * 1000 + a * 10000;
printf(" %d", Sn);
system(“pause”);
return 0;
}