Timetable codeforces-946d (pretreatment + backpack)

Test instructions: N Days m class, the maximum can escape K class, every day in the school to stay in the sky for the first class to the last lesson lasted time. Ask how to skip class can make this n days in school to stay the shortest time, output the shortest time.

Analysis:

1, pre-treatment of the daily Escape J class in the shortest time of school stay. T[I][J]

2, Dp[i][j] for the first day to escape J class stay in school the shortest time.

#include <bits/stdc++.h>using namespace Std;const int maxn = + 10;const int INF = 0x3f3f3f3f;char PIC[MAXN][MAXN]    ;vector<int> v[maxn];int t[maxn][maxn];int dp[maxn][maxn];int main () {int n, m, K;    scanf ("%d%d%d", &n, &m, &k);    for (int i = 1; I <= n; ++i) {scanf ("%s", Pic[i]);                } for (int i = 1, i <= N; ++i) {for (int j = 0; j < m; ++j) {if (pic[i][j] = = ' 1 ') {            V[i].push_back (j);        }}} for (int i = 1; I <= n; ++i) {int len = v[i].size ();        int mi = min (len, k);            for (int j = 0; J <= mi; ++j) {//truancy int rest = Len-j;                if (rest = = 0) {//No classes today t[i][j] = 0;            Continue            } int Mi = INF;                for (int w = 0; w < Len; ++w) {int et = w + rest-1;                if (et >= len) break;            mi = min (mi, v[i][et]-v[i][w] + 1); } T[i][j] = Mi;       }} for (int i = 1, i <= N; ++i) {for (int j = 0; j <= K; ++j) {dp[i][j] = INF;            for (int w = 0; w <= J; ++w) {Dp[i][j] = min (Dp[i][j], dp[i-1][w] + t[i][j-w]);    }}} printf ("%d\n", Dp[n][k]); return 0;}

　　

Timetable codeforces-946d (pretreatment + backpack)