【转】http://blog.youkuaiyun.com/zxy_snow/article/details/5959956
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <memory.h>
using namespace std;
int map[13];
int visit[13];
int sum;
int put[1000][13],str[13],len[1000];
int n,t,cou,num;
int flag;
void DFS(int d)
{
if( sum == t ) // 将所有的方案都存到二维数组里
{
len[num] = cou;
memcpy( put[num], str, cou*sizeof(int) );
num++;
flag = 1;
}
for(int i=d; i<=n; i++)
{
if( !visit[i] && sum + map[i] <= t )
{
visit[i] = 1;
str[cou] = map[i];
cou ++;
sum += map[i];
DFS(i+1);
visit[i] = 0;
sum -= map[i];
cou--;
}
}
}
int cmp( int i,int k) //判断两个数组是否相等,真悲剧啊,我用memcmp咋着都不对,为啥啊为啥啊。。
{
if(len[i] != len[k])
return 0;
for(int j=0; j<len[i]; j++)
if( put[i][j] != put[k][j] )
return 0;
return 1;
}
void output()
{
int jilu[1000];
memset(jilu,0,sizeof(jilu));
for(int i=0; i<num; i++) //如果有重复的,重复的标记下,下面输出没被标记的就OK
{
for(int k=i+1; k<num; k++)
if( cmp(i,k) && !jilu[k] )
{
jilu[k] = 1;
}
}
for(int i=0; i<num; i++)
if( jilu[i] == 0 )
{
cout << put[i][0];
for(int k=1; k<len[i]; k++)
cout << '+'<< put[i][k];
cout << endl;
}
}
int main(void)
{
while( cin >> t >> n && t )
{
for(int i=1; i<=n; i++)
cin >> map[i];
memset( visit,0,sizeof(visit) );
memset( put,0,sizeof(put) );
sum = 0; cou = 0; flag = 0; num = 0;
cout << "Sums of " << t << ":" << endl ;
DFS(1);
output();
if( flag == 0 )
cout << "NONE" << endl;
}
return 0;
}