看题解看到了Russ的分数加成法,优先dfs左边,回溯输出,再dfs右边。。。。。。。
code:
/* ID: yueqiq LANG: C++ TASK: frac1 */ #include <set> #include <map> #include <ctime> #include <queue> #include <cmath> #include <stack> #include <limits> #include <vector> #include <bitset> #include <string> #include <cstdio> #include <cstring> #include <fstream> #include <string.h> #include <iostream> #include <algorithm> #define ls rt<<1 #define rs rt<<1|1 #define Si set<int> #define LL long long #define pb push_back #define PS printf(" ") #define Vi vector<int> #define LN printf("\n") #define SD(a) scanf("%d",&a) #define PD(a) printf("%d",a) #define SET(a,b) memset(a,b,sizeof(a)) #define FF(i,a) for(int i(0);i<(a);i++) #define FD(i,a) for(int i(a);i>=(1);i--) #define FOR(i,a,b) for(int i(a);i<=(b);i++) #define FOD(i,a,b) for(int i(a);i>=(b);i--) #define readf freopen("frac1.in","r",stdin) #define writef freopen("frac1.out","w",stdout) const double pi = acos(-1.0); const int maxn = 50; const int BigP = 99999999; const int INF = 99999999; const int dx[]={0,1,0,-1}; const int dy[]={1,0,-1,0}; using namespace std; int N,ans; //a1/b1第一个分数 a2/b2第二个分数 void dfs(int a1,int b1,int a2,int b2){ if(a1+a2>N||b1+b2>N) return ; int m1=a1+a2,m2=b1+b2; dfs(a1,b1,m1,m2); printf("%d/%d\n",m1,m2); dfs(m1,m2,a2,b2); } int main(){ readf; writef; SD(N); puts("0/1"); dfs(0,1,1,1); puts("1/1"); return 0; }