#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 100000
#define INF 0x3f3f3f3f3f3f3f3fLL
unsigned int X = 12345;
int rand_() {
return (X *= 3) >> 1;
}
int *ej[N], eo[N], *ew[N], eo_[N];
void append(int **ej, int *eo, int i, int j) {
int o = eo[i]++;
if (o >= 2 && (o & o - 1) == 0)
ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
ej[i][o] = j;
}
long long dd[N]; int iq[N + 1], pq[N], cnt;
int lt(int i, int j) { return dd[i] < dd[j]; }
int p2(int p) {
return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}
void pq_up(int i) {
int p, q, j;
for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_dn(int i) {
int p, q, j;
for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_add_last(int i) {
iq[pq[i] = ++cnt] = i;
}
int pq_remove_first() {
int i = iq[1], j = iq[cnt--];
if (j != i)
pq[j] = 1, pq_dn(j);
pq[i] = 0;
return i;
}
void sort(int *aa, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, a = aa[l + rand_() % (r - l)], tmp;
while (j < k)
if (aa[j] == a)
j++;
else if (aa[j] < a) {
tmp = aa[i], aa[i] = aa[j], aa[j] = tmp;
i++, j++;
} else {
k--;
tmp = aa[j], aa[j] = aa[k], aa[k] = tmp;
}
sort(aa, l, i);
l = k;
}
}
int main() {
static char visited[N];
int n, m, i, j, w, o;
scanf("%d%d", &n, &m);
for (i = 0; i < n; i++) {
ej[i] = (int *) malloc(2 * sizeof *ej[i]);
ew[i] = (int *) malloc(2 * sizeof *ew[i]);
}
while (m--) {
scanf("%d%d%d", &i, &j, &w), i--, j--;
append(ej, eo, j, i), append(ew, eo_, i, w);
}
for (i = 0; i < n; i++)
sort(ew[i], 0, eo_[i]);
memset(dd, 0x3f, n * sizeof *dd), dd[n - 1] = 0, pq_add_last(n - 1);
while (cnt) {
i = pq_remove_first();
if (i == 0) {
printf("%lld\n", dd[i]);
return 0;
}
for (o = eo[i]; o--; ) {
j = ej[i][o];
if (!visited[j]) {
long long d = dd[i] + ew[j][--eo_[j]];
if (dd[j] > d) {
if (dd[j] == INF)
pq_add_last(j);
dd[j] = d, pq_up(j);
}
}
}
}
return 0;
}
Compilation message
ferries.c: In function 'append':
ferries.c:19:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
19 | if (o >= 2 && (o & o - 1) == 0)
| ~~^~~
ferries.c: In function 'main':
ferries.c:84:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
84 | scanf("%d%d", &n, &m);
| ^~~~~~~~~~~~~~~~~~~~~
ferries.c:90:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
90 | scanf("%d%d%d", &i, &j, &w), i--, j--;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
300 KB |
Output is correct |
| 2 |
Correct |
1 ms |
440 KB |
Output is correct |
| 3 |
Correct |
9 ms |
1708 KB |
Output is correct |
| 4 |
Correct |
120 ms |
14372 KB |
Output is correct |
| 5 |
Correct |
116 ms |
14296 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
1 ms |
436 KB |
Output is correct |
| 3 |
Correct |
8 ms |
1648 KB |
Output is correct |
| 4 |
Correct |
52 ms |
7312 KB |
Output is correct |
| 5 |
Correct |
58 ms |
11956 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
12 ms |
1796 KB |
Output is correct |
| 2 |
Correct |
12 ms |
1832 KB |
Output is correct |
| 3 |
Correct |
161 ms |
16420 KB |
Output is correct |
| 4 |
Correct |
174 ms |
16460 KB |
Output is correct |
| 5 |
Correct |
182 ms |
15744 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
165 ms |
16392 KB |
Output is correct |
| 2 |
Correct |
169 ms |
16396 KB |
Output is correct |
| 3 |
Correct |
148 ms |
16420 KB |
Output is correct |
| 4 |
Correct |
187 ms |
16476 KB |
Output is correct |
| 5 |
Correct |
201 ms |
16540 KB |
Output is correct |
