Submission #408989

#	Time	Username	Problem	Language	Result	Execution time	Memory
408989		ly20	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	1 ms	332 KiB

prison

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 4123;
int dp[MAXN][MAXN], dir[MAXN][MAXN];
int v[MAXN], mx[MAXN];
int main() {
    int n, d, t;
    scanf("%d %d %d", &n, &d, &t);
    for(int i = 1; i <= n; i++) {
        scanf("%d", &v[i]);
        mx[i] = 0;
    }
    for(int i = 1; i <= n; i++) {
        for(int j = 0; j <= i; j++) {
            mx[j] = max(mx[j], j + t - v[j]);
        }
        for(int j = 0; j <= n; j++) {
            //coloco:
            if(v[i] <= t) {
                if(j > 0) dp[i][j] = dp[i - 1][j - 1];
                else {
                        dp[i][j] = MAXN;
                    //printf("%d %d\n", i, j);
                }
                //printf("%d %d\n", i, j);
                if(j == 0) dir[i][j] = 0;
                else dir[i][j] = dir[i - 1][ j - 1];
            }
            else {
                int ls = dir[i - 1][j];
                /*if(i == 3 && j == 3) {
                    printf("%d %d\n", ls, mx[ls]);
                }*/
                int val = dp[i - 1][j];
                bool rb = false;
                if(mx[ls] >= i) rb = true;
                if(rb) {
                    dp[i][j] = dp[i - 1][j] + 1;
                    dir[i][j] = i;
                    if(j > 0 && dp[i - 1][j] + 1 > dp[i - 1][j - 1]) {
                        dp[i][j] = dp[i - 1][j - 1];
                        dir[i][j] = dir[i - 1][j - 1];
                    }
                }
                else {
                    dp[i][j] = dp[i - 1][j];
                    dir[i][j] = dir[i - 1][j];
                }
            }
            //printf("dp[%d][%d] = %d\n", i, j, dp[i][j]);
        }
    }
    int resp = MAXN;
    for(int i = 0; i <= n; i++) {
        if(dp[n][i] <= d) resp = min(i, resp);
        //printf("%d\n", dp[n][i]);
    }
    printf("%d\n", resp);
    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'int main()':
prison.cpp:34:21: warning: unused variable 'val' [-Wunused-variable]
   34 |                 int val = dp[i - 1][j];
      |                     ^~~
prison.cpp:8:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |     scanf("%d %d %d", &n, &d, &t);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
prison.cpp:10:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         scanf("%d", &v[i]);
      |         ~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20