【DP】 467C George and Job

简单DP。。。每个点有选和不选两种情况，推一下就好了。。。

#include <iostream>  #include <queue>  #include <stack>  #include <map>  #include <set>  #include <bitset>  #include <cstdio>  #include <algorithm>  #include <cstring>  #include <climits>#include <cstdlib>#include <cmath>#include <time.h>#define maxn 5005#define maxm 200005#define eps 1e-10#define mod 10000007#define INF 1e17#define lowbit(x) (x&(-x))#define mp make_pair#define ls o<<1#define rs o<<1 | 1#define lson o<<1, L, mid  #define rson o<<1 | 1, mid+1, R  typedef long long LL;//typedef int LL;using namespace std;LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}void scanf(int &__x){__x=0;char __ch=getchar();while(__ch==' '||__ch=='\n')__ch=getchar();while(__ch>='0'&&__ch<='9')__x=__x*10+__ch-'0',__ch = getchar();}LL gcd(LL _a, LL _b){if(!_b) return _a;else return gcd(_b, _a%_b);}// headLL dp[maxn][maxn], sum[maxn];int n, m, k;void read(void){scanf("%d%d%d", &n, &m, &k);for(int i = 1; i <= n; i++) scanf("%I64d", &sum[i]);for(int i = 1; i <= n; i++) sum[i] += sum[i-1];}void work(void){memset(dp, -1, sizeof dp);dp[0][0] = 0;for(int i = 0; i < n; i++)for(int j = 0; j <= k; j++) {if(dp[i][j] == -1) continue;dp[i+1][j] = max(dp[i][j], dp[i+1][j]);if(i + m <= n) dp[i+m][j+1] = max(dp[i+m][j+1], dp[i][j] + sum[i+m] - sum[i]);}printf("%I64d\n", dp[n][k]);}int main(void){read();work();return 0;}