luogu1220_关路灯 区间dp

传送门

区间dp

f[i][j][state] : [i, j]区间 state=0 当前选i state = 1 当前选j

注意枚举的顺序

转移的设计时 在同时刻不在【i,j】区间里的数也要考虑 不符合局部最优性

 #include <bits/stdc++.h>
 using namespace std;
 #define rep(i, a, b) for (int i = a; i <= b; ++i)

 ;

 ];

 inline int cal(int x, int y, int l, int r) {
     ]);
 }

 int main() {
     scanf("%d%d", &n, &c);

     memset(f, 0x3f, sizeof(f));
     f[c][c][] = f[c][c][] = ;

     rep(i, , n) {
         scanf("%d%d", &p[i], &v[i]);
         s[i] = s[i - ] + v[i];
     }

     rep(l, , n) rep(i, , n - l + ) {
         ;
         f[i][j][] = min(f[i + ][j][] + cal(i, i + , i + , j), f[i + ][j][] + cal(i, j, i + , j));
         f[i][j][] = min(f[i][j - ][] + cal(i, j, i, j - ), f[i][j - ][] + cal(j - , j, i, j - ));
     }

     printf(][n][], f[][n][]));

     ;
 }