十进制转十六进制

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <vector>
 4 #include <queue>
 5 #include <map>
 6 #include <stack>
 7 #include <cstring>
 8 #include <algorithm>
 9 #include <cstdlib>
10 #define FOR(i,x,n) for(long i=x;i<n;i++)
11 #define ll long long int
12 #define INF 0x3f3f3f3f
13 #define MOD 1000000007
14 #define MAX_N 50005
15 
16 using namespace std;
17 
18 char a[200000000];
19 
20 int main()
21 {
22     //freopen("input1.txt", "r", stdin);
23     //freopen("data.out", "w", stdout);
24     ll n;
25     int cou=0;
26     scanf("%lld",&n);
27     if(n==0){
28         printf("0");
29     }
30     while(n!=0){
31         int t=n%16;
32         if(t>=10){
33             a[cou++]=n%16-10+'A';
34         }else{
35             a[cou++]=n%16-1+'1';
36         }
37         n/=16;
38     }
39     for(int i=cou-1;i>=0;i--){
40         printf("%c",a[i]);
41     }
42     //fclose(stdin);
43     //fclose(stdout);
44     return 0;
45 }