1.scanf(“%d/%d/%d”,&a,&b,&c)
这里如果输入02/02/02，a，b，c都被输入了2，忽略了0
来源： https://www.acwing.com/activity/content/code/content/7946218/

2。printf(“%d-%02d-%02d\n”,t/10000,t%10000/100,t%100);
来源： https://www.acwing.com/activity/content/code/content/7946218/

3.getcline和stringstream一起使用提取含有空格的字符串中的信息
基本格式

string s;
int a[N];
getline(cin,s);
stringstream ssin(s);
while(ssin>>a[i])   i++;

例子：
https://www.acwing.com/activity/content/code/content/7936273/
单词替换https://www.acwing.com/activity/content/code/content/7583534/

4.sscanf的使用——按格式读取字符串内的信息
sscanf(const char str, const char format, …)

#include <bits/stdc++.h>
using namespace std;

int main()
{
    char a[20]="2004 2 21";
    string b="2004 5 16";
    int y1,m1,d1,y2,m2,d2;
    sscanf(a,"%d %d %d",&y1,&m1,&d1);
    sscanf(b.c_str(),"%d %d %d",&y2,&m2,&d2);
    printf("%d %d %d\n%d %d %d",y1,m1,d1,y2,m2,d2);
    //输出结果
    2004 2 21
    2004 5 16
    return 0;
}

例子： https://www.acwing.com/activity/content/code/content/7951909/

5.cin读入十六进制
例子