hdu 1560 迭代加深搜索

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

char g[10][10];
int size[10];
char dna[4] = {‘A‘,‘C‘,‘G‘,‘T‘};
int n;

int dfs(int now, int l, int p[])//p[i]代表当前第i行字符串匹配了多少个了
{
    if(now > l)
        return 0;
    int maxn = 0;
    
    for(int i=0; i<n; i++)//剪枝，查找至少还需要多少深度
    {
        maxn = max(maxn, size[i] -p[i]);
    }
    
    if(maxn == 0)
    {
        return now;
    }
    
    if(now + maxn > l) //如果至少需要的深度加上当前的深度比限制深度大，那么就剪掉
        return 0;
    for(int i = 0; i<4; i++)
    {
        int flag = 0;
        int temp[10] = {0};
        for(int j = 0; j<n; j++)
        {
            if(g[j][p[j]] == dna[i])//满足条件
            {
                flag = 1;
                temp[j] = p[j] + 1;
            }
            else
                temp[j] = p[j];
        }
        if(flag == 1)//只有满足条件才递归下去
        {
            int t = dfs(now+1, l, temp);
            if(t != 0)
            {
                return t;
            }
        }
    }
    return 0;
}


int main()
{
    int num;
    cin>>num;
    
    int maxn = -1;
    while(num--)
    {
        maxn = -1;
        memset(size, 0, sizeof(size));
        scanf("%d", &n);
        
        for(int i=0;i <n; i++)
        {
            scanf("%s", g[i]);
            size[i] = strlen(g[i]);
            maxn = max(maxn, size[i]);
        }
        
        int ans;
        int p[10] = {0};
        for(int i=maxn; ; i++)
        {
            if(dfs(0, i, p))
            {
                ans = i;
                break;
            }
        }
        
        cout<<ans<<endl;
    }
    
    return 0;
}