链接:https://ac.nowcoder.com/acm/problem/15128
来源:牛客网
题目描述
老李见和尚赢了自己的酒,但是自己还舍不得,所以就耍起了赖皮,对和尚说,光武不行,再来点文的,你给我说出来1-8的全排序,我就让你喝,这次绝不耍你,你能帮帮和尚么?
输入描述:
无
输出描述:
1~8的全排列,按照全排列的顺序输出,每行结尾无空格。
示例1
输入
复制
No_Input
输出
复制
Full arrangement of 1~8
备注:
1~3的全排列 :
1 2 3
1 3 2
2 1 3
2 3 1
3 1 2
3 2 1
求全排列是dfs的基本功了
#ifdef debug
#include <time.h>
#include "/home/majiao/mb.h"
#endif
#include <iostream>
#include <algorithm>
#include <vector>
#include <string.h>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <math.h>
#define MAXN (16)
#define ll long long int
#define INF (0x7f7f7f7f)
#define fori(lef, rig) for(int i=lef; i<=rig; i++)
#define forj(lef, rig) for(int j=lef; j<=rig; j++)
#define fork(lef, rig) for(int k=lef; k<=rig; k++)
#define QAQ (0)
using namespace std;
#ifdef debug
#define show(x...) \ do { \ cout << "\033[31;1m " << #x << " -> "; \ err(x); \ } while (0)
void err() { cout << "\033[39;0m" << endl; }
template<typename T, typename... A>
void err(T a, A... x) { cout << a << ' '; err(x...); }
#endif
#ifndef debug
namespace FIO {
template <typename T>
void read(T& x) {
int f = 1; x = 0;
char ch = getchar();
while (ch < '0' || ch > '9')
{ if (ch == '-') f = -1; ch = getchar(); }
while (ch >= '0' && ch <= '9')
{ x = x * 10 + ch - '0'; ch = getchar(); }
x *= f;
}
};
using namespace FIO;
#endif
int n = 8, m, Q, K, rs[MAXN], a[MAXN], vis[MAXN];
void dfs(int level) {
if(level == n+1) {
for(int i=1; i<=n; i++)
printf("%d%c", a[rs[i]], i==n?'\n':' ');
return ;
}
for(int i=1; i<=n; i++) {
if(!vis[i]) {
vis[i] = true;
rs[level] = i;
dfs(level+1);
vis[i] = false;
}
}
}
int main() {
#ifdef debug
freopen("test", "r", stdin);
clock_t stime = clock();
#endif
fori(1, 8) a[i] = i;
dfs(1);
#ifdef debug
clock_t etime = clock();
printf("rum time: %lf 秒\n",(double) (etime-stime)/CLOCKS_PER_SEC);
#endif
return 0;
}