#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int main() {
int i = 4;
double d = 4.0;
char s[] = "HackerRank ";
// Declare second integer, double, and String variables.声明第二个int ，double ,字符数组
int i1;
double d1;
char s1[200];
// Read and save an integer, double, and String to your variables.读取并保存上面输入的值
scanf("%d",&i1);
scanf("%lf",&d1);
scanf("%*[\n]%[^\n]",s1); //这里看上一篇预习的解析。
// Print the sum of both integer variables on a new line.打印两个整数的和
printf("%d\n",i+i1);
// Print the sum of the double variables on a new line.打印两个浮点数的和，并控制输出位数
printf("%.1lf\n",d+d1);
// Concatenate and print the String variables on a new line.连接两个字符串（考虑拼接函数）
printf("%s%s\n",s,s1);
// The ‘s‘ variable above should be printed first.
return 0;
