GCJ

#include <bits/stdc++.h>using namespace std;#define maxn 105#define INF 0x7ffffffint dp[maxn][maxn];int Q[maxn];int p, q;int main(){    while(~scanf("%d%d", &p, &q))    {        for(int i=1; i<=q; i++)            cin>>Q[i];        Q[0] = 0;        Q[q+1] = p+1;        for(int i=0; i<=q; i++)            dp[i][i+1] = 0;        for(int l=2; l<=q+1; l++)//根据j-i递增的顺序来递推            for(int i=0; i+l<=q+1; i++)        {            int j = i + l;            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]+Q[j]-Q[i]-2);        }        cout<<dp[0][q+1]<<endl;    }    return 0;}