Submission #399439

#	Time	Username	Problem	Language	Result	Execution time	Memory
399439		duality	Sparklers (JOI17_sparklers)	C++11	0 / 100	1 ms	304 KiB

sparklers

#define DEBUG 0

#include <bits/stdc++.h>
using namespace std;

#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}

// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
    public:
        template<typename T>
        _Debug& operator,(T val) {
            cout << val << endl;
            return *this;
        }
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif

// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back

// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;

// ---------- END OF TEMPLATE ----------

int X[100000];
int main() {
    int i;
    int N,K,T;
    scanf("%d %d %d",&N,&K,&T),K--;
    for (i = 0; i < N; i++) scanf("%d",&X[i]);

    int j;
    int s = 0,e = 1e9;
    while (s < e) {
        int m = (s+e) / 2;

        i = j = K;
        LLI l = X[K],r = X[K];
        while ((i > 0) || (j < N-1)) {
            int x = 0;
            if (i == 0) x = 1;
            else if (j == N-1) x = 0;
            else if (X[i]-X[i-1] < X[j+1]-X[j]) x = 0;
            else x = 1;
            if (x == 0) {
                int t = j-i+1;
                LLI L = max(X[i-1]-(LLI) t*m,l-m);
                LLI R = min(X[i-1]+(LLI) t*m,r+m);
                if (L <= R) l = L,r = R,i--;
                else break;
            }
            else {
                int t = j-i+1;
                LLI L = max(X[j+1]-(LLI) t*m,l-m);
                LLI R = min(X[j+1]+(LLI) t*m,r+m);
                if (L <= R) l = L,r = R,j++;
                else break;
            }
        }
        if ((i == 0) && (j == N-1)) e = m;
        else s = m+1;
/*
        for (i = K; i >= 0; i--) {
            for (j = K; j < N; j++) {
                if ((i == K) && (j == K)) l[K][K] = r[K][K] = X[K];
                else {
                    l[i][j] = 1e18,r[i][j] = -1e18;
                    int t = j-i;
                    if (i < K) {
                        LLI L = max(X[i]-(LLI) t*m,l[i+1][j]-m);
                        LLI R = min(X[i]+(LLI) t*m,r[i+1][j]+m);
                        if (L <= R) l[i][j] = min(l[i][j],L),r[i][j] = max(r[i][j],R);
                    }
                    if (j > K) {
                        LLI L = max(X[j]-(LLI) t*m,l[i][j-1]-m);
                        LLI R = min(X[j]+(LLI) t*m,r[i][j-1]+m);
                        if (L <= R) l[i][j] = min(l[i][j],L),r[i][j] = max(r[i][j],R);
                    }
                }
            }
        }
        if (l[0][N-1] <= r[0][N-1]) e = m;
        else s = m+1;*/
    }
    printf("%d\n",(s+T-1)/T);

    return 0;
}

Compilation message (stderr)

sparklers.cpp: In function 'int main()':
sparklers.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   62 |     scanf("%d %d %d",&N,&K,&T),K--;
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:63:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   63 |     for (i = 0; i < N; i++) scanf("%d",&X[i]);
      |                             ~~~~~^~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50