m,n=map(int,input().split())
la=list(map(int,input().split())
maxsize=m+1
lb=[-1]*maxsize;head=tail=0
ans=0
def f(lt,s,e,t,mx):
    flag=False
    while s!e:
        if t==lt[s]:
            flag=True
            break
        s=(s+1)%mx
    return flag
for i in range(n):
    t=la[i]
    if not f(lb,hea,tail,t,maxsize):
        if

C++

😕

实测可行，但为什么两个测试点longer than standard output，这两个点应该过才对😕

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

string t = "0123456789ABCDEF";

string change(int a) {
    int x;
    string s;
    while(a != 0) {
        x = a % 16;
        s = t[x] + s;
        a = a / 16;
    }
    if (s == "") return "00";
    if (s.length() == 1) return "0" + s;
    else return s;
}

int main(){
    string s;
    char x;
    int y;
    cin >> s >> x >> y;
    int j;
    if(x == 'R') j = 1;
    if(x == 'G') j = 3;
    if(x == 'B') j = 5;
    for(int i = 0; i <= 6; i ++) {
        if (i > 6) break;
        if(i == j) {
            cout << change(y);
            i += 2;
        }
        cout << s[i];
    }
    return 0;
}

我们需要两个模块：一是十进制转十六进制，二是十六进制转十进制（注意0的特判）

#include <bits/stdc++.h>
using namespace std;
const string thex = "0123456789ABCDEF";

int to_dec(string s)
{
	return 16*thex.find(s[0])+thex.find(s[1]);
}

string to_hex(int n)
{
	if(n == 0) return "00";
	string t = "";
	while(n)
	{
		t=thex[n%16]+t;
		n/=16;
	}
	return t;
}

int main()
{
	string s;
	char x;
	int t;
	cin >> s >> x >> t;
	cout << "#";
	if(x == 'R')
	{
		cout << to_hex(t);
		for(int i=3;i<s.size();i++) cout << s[i];
	}
	else if(x == 'G')
	{
		for(int i=1;i<=2;i++) cout << s[i];
		cout << to_hex(t);
		for(int i=5;i<s.size();i++) cout << s[i];
	}
	else if(x == 'B')
	{
		for(int i=1;i<=4;i++) cout << s[i];
		cout << to_hex(t);
	}
	return 0;
}