Power Calculus UVA - 1374 迭代加深搜索

迭代加深搜索经典题目，好久不做迭代加深搜索题目，拿来复习了，我们直接对当前深度进行搜索，注意剪枝，还有数组要适当开大，因为2^maxd可能很大

题目：题目链接

AC代码：

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <set>

#define FRER() freopen("in.txt", "r", stdin);
#define INF 0x3f3f3f3f

using namespace std;

const int maxn = 10000 + 5;

int num[maxn], vis[maxn], temp[50], maxd, n;

bool dfs(int, int);

int main()
{
//FRER()
ios::sync_with_stdio(0);
cin.tie(0);

temp[0] = 1;
for(int i = 1; i < 32; ++ i)
temp[i] = temp[i - 1] << 1;
while(cin >> n && n) {
memset(vis, 0, sizeof(vis));
for(maxd = 0; ; ++maxd)
if(dfs(0, 1)) break;
cout << maxd << endl;
}
return 0;
}

bool dfs(int cur, int s) {
if(cur == maxd && s == n) return true;
if(cur > maxd) return false;
if(s * temp[maxd - cur] < n) return false;
num[cur] = s;
vis[s] = 1;
for(int i = 0; i <= cur; ++i) {
int u = num[i] + s;
if(!vis[u]) {
vis[u] = 1;
if(dfs(cur + 1, u)) return true;
vis[u] = 0;
}
u = abs(num[i] - s);
if(!vis[u]) {
vis[u] = 1;
if(dfs(cur + 1, u)) return true;
vis[u] = 0;
}
}
vis[s] = 0;
return false;
}