Cutting Sticks
题意:
l长的木棒,给出n个切割点,每切一次的费用为切得木棒的长度,完成切割的最小费用。
分析:
区间dp入门,区间dp的特点,一个大区间的解可以转换成小区间的解组合起来,每个切割点的标号代表边界。
#include <map> #include <set> #include <list> #include <cmath> #include <queue> #include <stack> #include <cstdio> #include <vector> #include <string> #include <cctype> #include <complex> #include <cassert> #include <utility> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> using namespace std; typedef pair<int,int> PII; typedef long long ll; #define lson l,m,rt<<1 #define pi acos(-1.0) #define rson m+1,r,rt<<11 #define All 1,N,1 #define read freopen("in.txt", "r", stdin) const ll INFll = 0x3f3f3f3f3f3f3f3fLL; const int INF= 0x7ffffff; const int mod = 1000000007; int dp[100][100],c[100],n,l; void solve(){ c[0]=0; c[n+1]=l; memset(dp,0,sizeof(dp)); for(int p=2;p<=n+1;++p) for(int i=0;i<=n-p+1;++i) { int j=i+p; dp[i][j]=INF; for(int k=i+1;k<j;++k) dp[i][j]=min(dp[i][j],dp[i][k]+dp[k][j]+c[j]-c[i]); } printf("The minimum cutting is %d.\n",dp[0][n+1]); } int main() { while(~scanf("%d",&l)){ if(l==0)break; scanf("%d",&n); for(int i=1;i<=n;++i) scanf("%d",&c[i]); solve(); } return 0; }