Given a consecutive number sequence S₁, S₂, S₃, S₄ ... S_x, ... S_n (1 ≤ x ≤ n ≤ 1,000,000, -32768 ≤ S_x ≤ 32767). We define a function sum(i, j) = S_i + ... + S_j (1 ≤ i ≤ j ≤ n).

Now given an integer m (m > 0), your task is to find m pairs of i and j which make sum(i₁, j₁) + sum(i₂, j₂) + sum(i₃, j₃) + ... + sum(i_m, j_m) maximal (i_x ≤ i_y ≤ j_x or i_x ≤ j_y ≤ j_x is not allowed).

But I`m lazy, I don't want to write a special-judge module, so you don't have to output m pairs of i and j, just output the maximal summation of sum(i_x, j_x)(1 ≤ x ≤ m) instead. ^_^

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

using namespace std;

int dp[][],a[];

int main()

{

    int n,m,j,i,k,Max;

    while(~scanf("%d%d",&m,&n)){

        Max=;

        memset(dp,,sizeof(dp));

        for(i=;i<=n;i++) scanf("%d",&a[i]);

        for(i=;i<=m;i++)

         for(j=i+1;j<=n;j++){

                dp[i%][j]=dp[i%][j-]+a[j];

                for(k=i-;k<=j-;k++)

                 if(dp[(i-)%][k]+a[j]>dp[i%][j]) dp[i%][j]=dp[(i-)%][k]+a[j];

                if(i==m&&dp[i%][j]>Max) Max=dp[i%][j];

         }

         printf("%d\n",Max);

    }

    return ;

}

#include<cstdio>

#include<cstdlib>

#include<iostream>

#include<memory.h>

using namespace std;

int dp[][],a[];

int main()

{

    int n,m,j,i,k,Max,Maxp;

    while(~scanf("%d%d",&m,&n)){

        Max=-;

        for(i=;i<=n;i++) scanf("%d",&a[i]);

        for(i=;i<=n;i++) dp[][i]=dp[][i]=;

         for(i=;i<=m;i++) {

           Maxp=dp[(i-)%][i-];

           dp[i%][i]=dp[(i-)%][i-]+a[i];

           for(j=i+;j<=n-m+i;j++){

                if(dp[(i-)%][j-]>Maxp) Maxp=dp[(i-)%][j-];

                dp[i%][j]=dp[i%][j-]+a[j];

                if(Maxp+a[j]>dp[i%][j]) dp[i%][j]=Maxp+a[j];

         }

        }

         for(i=m;i<=n;i++)

           if(dp[m%][i]>Max) Max=dp[m%][i];

         printf("%d\n",Max);

    }

    return ;

}

至于此题的数据范围，呵呵，不存在的。