Submission #413214

#	Time	Username	Problem	Language	Result	Execution time	Memory
413214		LptN21	K blocks (IZhO14_blocks)	C++14	100 / 100	295 ms	43528 KiB

blocks

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
#define FF first
#define SS second
#define pb push_back
#define sz(x) (int)x.size()
#define oo 1e9
#define PI acos(-1.0)
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
const int N = 100000+7, M=100+7;
const ll MOD = 1e9+7;

int n, m, k, t;

int a[N], _dp[N][M];

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d%d", &n, &m);
    for(int i=1;i<=n;scanf("%d", &a[i++]))
        for(int j=0;j<=m;j++) _dp[i][j]=oo;
    for(int i=0;i<=m;i++) _dp[0][i]=oo;_dp[0][1]=0;
    for(int i=1;i<=n;i++) _dp[i][1]=max(_dp[i-1][1], a[i]);
    for(int mn, j=2;j<=m;j++) {
        stack<ii> st;
        for(int i=j;i<=n;i++) {
            mn=_dp[i-1][j-1];
            while(sz(st)&&a[st.top().SS]<=a[i])
                mn=min(st.top().FF, mn), st.pop();
            _dp[i][j]=min(_dp[sz(st)?st.top().SS:0][j], mn+a[i]);
            st.push(ii(mn, i));
        }
    }
    printf("%d", _dp[n][m]);
    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special cases (n=1?)
    - do smth instead of do nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:29:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   29 |     for(int i=0;i<=m;i++) _dp[0][i]=oo;_dp[0][1]=0;
      |     ^~~
blocks.cpp:29:40: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   29 |     for(int i=0;i<=m;i++) _dp[0][i]=oo;_dp[0][1]=0;
      |                                        ^~~
blocks.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
blocks.cpp:27:27: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     for(int i=1;i<=n;scanf("%d", &a[i++]))
      |                      ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47