很久没写了，最近做了一下，感觉代码能力更糟了。
#include<set>
#include<map>
#include<vector>
#include<string>
#include<algorithm>
#include<iostream>
#include<queue>
using namespace std;
vector<int>num;
vector<int>res;
int min_digit(int pos,int len)
{
int smin=INT_MAX;
int k=-1;
for(int i=pos;i<len;i++)
{
if(num[i]!=0 && num[i]<smin)
{
k=i;
smin=num[i];
}
}
return k;
}
int min_digit_bigger(int pos,int len)
{
int smin=INT_MAX;
int k=-1;
for(int i=pos;i<len;i++)
{
if(num[i]<smin && num[i]>num[pos-1])
{
k=i;
smin=num[i];
}
}
return k;
}
void solve()
{
int len=num.size();
int pos;
for(pos=len-1;pos>0 && num[pos]<=num[pos-1];pos--);
if(pos==0)
{
int min_pos=min_digit(pos,len);
if(min_pos==-1)
{
res.push_back(num[0]);
}
else
{
res.push_back(num[min_pos]);
num[min_pos]=0;
}
res.push_back(0);
sort(num.begin(),num.end());
for(int i=1;i<len;i++)
res.push_back(num[i]);
}
else
{
for(int i=0;i<pos-1;i++)
res.push_back(num[i]);
int min_pos_bigger=min_digit_bigger(pos,len);
res.push_back(num[min_pos_bigger]);
num[min_pos_bigger]=0;
vector<int>tmp;
for(int i=pos-1;i<len;i++)
tmp.push_back(num[i]);
sort(tmp.begin(),tmp.end());
for(int i=1;i<tmp.size();i++)
res.push_back(tmp[i]);
}
}
int main()
{
freopen("in","r",stdin);
freopen("out.txt","w",stdout);
char ch;
int caseNum;
cin>>caseNum;
getchar();
for(int caseId=1;caseId<=caseNum;caseId++)
{
num.clear();
res.clear();
while((ch=getchar())!='\n')
{
num.push_back(ch-'0');
}
solve();
cout<<"Case #"<<caseId<<": ";
for(int i=0;i<res.size();i++)
cout<<res[i];
cout<<endl;
}
}
写完之后看了ACRush的代码。刚开始没看懂，以为他随便提交了一个程序，因为他只用了next_permutation.后来才领悟。原来next_permutation会自动生成下一个逻辑较大的排列。发下他的代码膜拜下
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
using namespace std;
//BEGINTEMPLATE_BY_ACRUSH_TOPCODER
#define SIZE(X) ((int)(X.size()))//NOTES:SIZE(
#define LENGTH(X) ((int)(X.length()))//NOTES:LENGTH(
#define MP(X,Y) make_pair(X,Y)//NOTES:MP(
typedef long long int64;//NOTES:int64
typedef unsigned long long uint64;//NOTES:uint64
#define two(X) (1<<(X))//NOTES:two(
#define twoL(X) (((int64)(1))<<(X))//NOTES:twoL(
#define contain(S,X) (((S)&two(X))!=0)//NOTES:contain(
#define containL(S,X) (((S)&twoL(X))!=0)//NOTES:containL(
const double pi=acos(-1.0);//NOTES:pi
const double eps=1e-11;//NOTES:eps
template<class T> inline void checkmin(T &a,T b){if(b<a) a=b;}//NOTES:checkmin(
template<class T> inline void checkmax(T &a,T b){if(b>a) a=b;}//NOTES:checkmax(
template<class T> inline T sqr(T x){return x*x;}//NOTES:sqr
typedef pair<int,int> ipair;//NOTES:ipair
template<class T> inline T lowbit(T n){return (n^(n-1))&n;}//NOTES:lowbit(
template<class T> inline int countbit(T n){return (n==0)?0:(1+countbit(n&(n-1)));}//NOTES:countbit(
//Numberic Functions
template<class T> inline T gcd(T a,T b)//NOTES:gcd(
{if(a<0)return gcd(-a,b);if(b<0)return gcd(a,-b);return (b==0)?a:gcd(b,a%b);}
template<class T> inline T lcm(T a,T b)//NOTES:lcm(
{if(a<0)return lcm(-a,b);if(b<0)return lcm(a,-b);return a*(b/gcd(a,b));}
template<class T> inline T euclide(T a,T b,T &x,T &y)//NOTES:euclide(
{if(a<0){T d=euclide(-a,b,x,y);x=-x;return d;}
if(b<0){T d=euclide(a,-b,x,y);y=-y;return d;}
if(b==0){x=1;y=0;return a;}else{T d=euclide(b,a%b,x,y);T t=x;x=y;y=t-(a/b)*y;return d;}}
template<class T> inline vector<pair<T,int> > factorize(T n)//NOTES:factorize(
{vector<pair<T,int> > R;for (T i=2;n>1;){if (n%i==0){int C=0;for (;n%i==0;C++,n/=i);R.push_back(make_pair(i,C));}
i++;if (i>n/i) i=n;}if (n>1) R.push_back(make_pair(n,1));return R;}
template<class T> inline bool isPrimeNumber(T n)//NOTES:isPrimeNumber(
{if(n<=1)return false;for (T i=2;i*i<=n;i++) if (n%i==0) return false;return true;}
template<class T> inline T eularFunction(T n)//NOTES:eularFunction(
{vector<pair<T,int> > R=factorize(n);T r=n;for (int i=0;i<R.size();i++)r=r/R[i].first*(R[i].first-1);return r;}
//Matrix Operations
const int MaxMatrixSize=40;//NOTES:MaxMatrixSize
template<class T> inline void showMatrix(int n,T A[MaxMatrixSize][MaxMatrixSize])//NOTES:showMatrix(
{for (int i=0;i<n;i++){for (int j=0;j<n;j++)cout<<A[i][j];cout<<endl;}}
template<class T> inline T checkMod(T n,T m) {return (n%m+m)%m;}//NOTES:checkMod(
template<class T> inline void identityMatrix(int n,T A[MaxMatrixSize][MaxMatrixSize])//NOTES:identityMatrix(
{for (int i=0;i<n;i++) for (int j=0;j<n;j++) A[i][j]=(i==j)?1:0;}
template<class T> inline void addMatrix(int n,T C[MaxMatrixSize][MaxMatrixSize],T A[MaxMatrixSize][MaxMatrixSize],T B[MaxMatrixSize][MaxMatrixSize])//NOTES:addMatrix(
{for (int i=0;i<n;i++) for (int j=0;j<n;j++) C[i][j]=A[i][j]+B[i][j];}
template<class T> inline void subMatrix(int n,T C[MaxMatrixSize][MaxMatrixSize],T A[MaxMatrixSize][MaxMatrixSize],T B[MaxMatrixSize][MaxMatrixSize])//NOTES:subMatrix(
{for (int i=0;i<n;i++) for (int j=0;j<n;j++) C[i][j]=A[i][j]-B[i][j];}
template<class T> inline void mulMatrix(int n,T C[MaxMatrixSize][MaxMatrixSize],T _A[MaxMatrixSize][MaxMatrixSize],T _B[MaxMatrixSize][MaxMatrixSize])//NOTES:mulMatrix(
{ T A[MaxMatrixSize][MaxMatrixSize],B[MaxMatrixSize][MaxMatrixSize];
for (int i=0;i<n;i++) for (int j=0;j<n;j++) A[i][j]=_A[i][j],B[i][j]=_B[i][j],C[i][j]=0;
for (int i=0;i<n;i++) for (int j=0;j<n;j++) for (int k=0;k<n;k++) C[i][j]+=A[i][k]*B[k][j];}
template<class T> inline void addModMatrix(int n,T m,T C[MaxMatrixSize][MaxMatrixSize],T A[MaxMatrixSize][MaxMatrixSize],T B[MaxMatrixSize][MaxMatrixSize])//NOTES:addModMatrix(
{for (int i=0;i<n;i++) for (int j=0;j<n;j++) C[i][j]=checkMod(A[i][j]+B[i][j],m);}
template<class T> inline void subModMatrix(int n,T m,T C[MaxMatrixSize][MaxMatrixSize],T A[MaxMatrixSize][MaxMatrixSize],T B[MaxMatrixSize][MaxMatrixSize])//NOTES:subModMatrix(
{for (int i=0;i<n;i++) for (int j=0;j<n;j++) C[i][j]=checkMod(A[i][j]-B[i][j],m);}
template<class T> inline T multiplyMod(T a,T b,T m) {return (T)((((int64)(a)*(int64)(b)%(int64)(m))+(int64)(m))%(int64)(m));}//NOTES:multiplyMod(
template<class T> inline void mulModMatrix(int n,T m,T C[MaxMatrixSize][MaxMatrixSize],T _A[MaxMatrixSize][MaxMatrixSize],T _B[MaxMatrixSize][MaxMatrixSize])//NOTES:mulModMatrix(
{ T A[MaxMatrixSize][MaxMatrixSize],B[MaxMatrixSize][MaxMatrixSize];
for (int i=0;i<n;i++) for (int j=0;j<n;j++) A[i][j]=_A[i][j],B[i][j]=_B[i][j],C[i][j]=0;
for (int i=0;i<n;i++) for (int j=0;j<n;j++) for (int k=0;k<n;k++) C[i][j]=(C[i][j]+multiplyMod(A[i][k],B[k][j],m))%m;}
template<class T> inline T powerMod(T p,int e,T m)//NOTES:powerMod(
{if(e==0)return 1%m;else if(e%2==0){T t=powerMod(p,e/2,m);return multiplyMod(t,t,m);}else return multiplyMod(powerMod(p,e-1,m),p,m);}
//Point&Line
double dist(double x1,double y1,double x2,double y2){return sqrt(sqr(x1-x2)+sqr(y1-y2));}//NOTES:dist(
double distR(double x1,double y1,double x2,double y2){return sqr(x1-x2)+sqr(y1-y2);}//NOTES:distR(
template<class T> T cross(T x0,T y0,T x1,T y1,T x2,T y2){return (x1-x0)*(y2-y0)-(x2-x0)*(y1-y0);}//NOTES:cross(
int crossOper(double x0,double y0,double x1,double y1,double x2,double y2)//NOTES:crossOper(
{double t=(x1-x0)*(y2-y0)-(x2-x0)*(y1-y0);if (fabs(t)<=eps) return 0;return (t<0)?-1:1;}
bool isIntersect(double x1,double y1,double x2,double y2,double x3,double y3,double x4,double y4)//NOTES:isIntersect(
{return crossOper(x1,y1,x2,y2,x3,y3)*crossOper(x1,y1,x2,y2,x4,y4)<0 && crossOper(x3,y3,x4,y4,x1,y1)*crossOper(x3,y3,x4,y4,x2,y2)<0;}
bool isMiddle(double s,double m,double t){return fabs(s-m)<=eps || fabs(t-m)<=eps || (s<m)!=(t<m);}//NOTES:isMiddle(
//Translator
bool isUpperCase(char c){return c>='A' && c<='Z';}//NOTES:isUpperCase(
bool isLowerCase(char c){return c>='a' && c<='z';}//NOTES:isLowerCase(
bool isLetter(char c){return c>='A' && c<='Z' || c>='a' && c<='z';}//NOTES:isLetter(
bool isDigit(char c){return c>='0' && c<='9';}//NOTES:isDigit(
char toLowerCase(char c){return (isUpperCase(c))?(c+32):c;}//NOTES:toLowerCase(
char toUpperCase(char c){return (isLowerCase(c))?(c-32):c;}//NOTES:toUpperCase(
template<class T> string toString(T n){ostringstream ost;ost<<n;ost.flush();return ost.str();}//NOTES:toString(
int toInt(string s){int r=0;istringstream sin(s);sin>>r;return r;}//NOTES:toInt(
int64 toInt64(string s){int64 r=0;istringstream sin(s);sin>>r;return r;}//NOTES:toInt64(
double toDouble(string s){double r=0;istringstream sin(s);sin>>r;return r;}//NOTES:toDouble(
template<class T> void stoa(string s,int &n,T A[]){n=0;istringstream sin(s);for(T v;sin>>v;A[n++]=v);}//NOTES:stoa(
template<class T> void atos(int n,T A[],string &s){ostringstream sout;for(int i=0;i<n;i++){if(i>0)sout<<' ';sout<<A[i];}s=sout.str();}//NOTES:atos(
template<class T> void atov(int n,T A[],vector<T> &vi){vi.clear();for (int i=0;i<n;i++) vi.push_back(A[i]);}//NOTES:atov(
template<class T> void vtoa(vector<T> vi,int &n,T A[]){n=vi.size();for (int i=0;i<n;i++)A[i]=vi[i];}//NOTES:vtoa(
template<class T> void stov(string s,vector<T> &vi){vi.clear();istringstream sin(s);for(T v;sin>>v;vi.push_bakc(v));}//NOTES:stov(
template<class T> void vtos(vector<T> vi,string &s){ostringstream sout;for (int i=0;i<vi.size();i++){if(i>0)sout<<' ';sout<<vi[i];}s=sout.str();}//NOTES:vtos(
//Fraction
template<class T> struct Fraction{T a,b;Fraction(T a=0,T b=1);string toString();};//NOTES:Fraction
template<class T> Fraction<T>::Fraction(T a,T b){T d=gcd(a,b);a/=d;b/=d;if (b<0) a=-a,b=-b;this->a=a;this->b=b;}
template<class T> string Fraction<T>::toString(){ostringstream sout;sout<<a<<"/"<<b;return sout.str();}
template<class T> Fraction<T> operator+(Fraction<T> p,Fraction<T> q){return Fraction<T>(p.a*q.b+q.a*p.b,p.b*q.b);}
template<class T> Fraction<T> operator-(Fraction<T> p,Fraction<T> q){return Fraction<T>(p.a*q.b-q.a*p.b,p.b*q.b);}
template<class T> Fraction<T> operator*(Fraction<T> p,Fraction<T> q){return Fraction<T>(p.a*q.a,p.b*q.b);}
template<class T> Fraction<T> operator/(Fraction<T> p,Fraction<T> q){return Fraction<T>(p.a*q.b,p.b*q.a);}
//ENDTEMPLATE_BY_ACRUSH_TOPCODER
const int maxn=20+5;
int n;
int A[maxn];
int main()
{
// freopen("B.in","r",stdin);
// freopen("B-small-attempt0.in","r",stdin);freopen("B-small-attempt0.out","w",stdout);
// freopen("B-small-attempt1.in","r",stdin);freopen("B-small-attempt1.out","w",stdout);
freopen("B-large.in","r",stdin);freopen("B-large.out","w",stdout);
int testcase;
scanf("%d",&testcase);
for (int caseId=1;caseId<=testcase;caseId++)
{
char str[100];
scanf("%s",str);
n=0;
for (int i=0;str[i];i++) A[n++]=str[i]-'0';
if (next_permutation(A,A+n)==0)
{
n=0;
A[n++]=0;
for (int i=0;str[i];i++) A[n++]=str[i]-'0';
next_permutation(A,A+n);
}
printf("Case #%d: ",caseId);
for (int i=0;i<n;i++)
printf("%d",A[i]);
printf("\n");
}
return 0;
}