Submission #6352887


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#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
using std::min; using std::max;
using std::swap; using std::sort;
typedef long long ll;

template<typename T>
void read(T &x) {
	int flag = 1; x = 0; char ch = getchar();
	while(ch < '0' || ch > '9') { if(ch == '-') flag = -flag; ch = getchar(); }
	while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar(); x *= flag;
}

const int _ = 4e5 + 10;
int n, q, d[_], cnt, fa[_];
struct Edge { int u, v, w; } e[_];
inline bool operator < (const Edge &a, const Edge &b) { return a.w < b.w; }
inline void ChkMin(int &a, int b) { if(a > b) a = b; }
inline void addEdge(int u, int v, int w) { e[++cnt] = (Edge){u, v, w}; }
int find(int x) { return fa[x] == x ? x : fa[x] = find(fa[x]); }
bool unionn(int x, int y) {
	int fx = find(x), fy = find(y);
	if(fx == fy) return 0;
	fa[fx] = fy; return 1;
}

int main () {
#ifdef OFFLINE_JUDGE
	freopen("233.in", "r", stdin);
	freopen("233.out", "w", stdout);
#endif
	read(n), read(q);
	memset(d, 127, sizeof d);
	for(int i = 1, a, b, c; i <= q; ++i) {
		read(a), read(b), read(c), addEdge(a, b, c);
		ChkMin(d[a], c + 1), ChkMin(d[b], c + 2);
	}
	for(int i = 0; i < n; ++i) ChkMin(d[i], d[(i - 1 + n) % n] + 2);
	for(int i = 0; i < n; ++i) ChkMin(d[i], d[(i - 1 + n) % n] + 2);
	for(int i = 0; i <= n; ++i) addEdge(i, (i + 1) % n, d[i]);
	sort(e + 1, e + cnt + 1);
	for(int i = 1; i < n; ++i) fa[i] = i;
	int blo = n; ll ans = 0;
	for(int i = 1; i <= cnt && blo > 1; ++i)
		if(unionn(e[i].u, e[i].v)) ans += e[i].w, --blo;
	printf("%lld\n", ans);
	return 0;
} 

Submission Info

Submission Time
Task G - Zigzag MST
User vjudge2
Language C++14 (GCC 5.4.1)
Score 1300
Code Size 1578 Byte
Status
Exec Time 74 ms
Memory 10240 KB

Judge Result

Set Name Score / Max Score Test Cases
sample 0 / 0 sample-01.txt, sample-02.txt, sample-03.txt
all 1300 / 1300 sample-01.txt, sample-02.txt, sample-03.txt, 01-01.txt, 01-02.txt, 01-03.txt, 01-04.txt, 01-05.txt, 01-06.txt, 01-07.txt, 01-08.txt, 01-09.txt, 01-10.txt, 01-11.txt, 01-12.txt, 01-13.txt, 01-14.txt, 01-15.txt, 01-16.txt, 01-17.txt, 01-18.txt, 01-19.txt, 01-20.txt, 01-21.txt, 01-22.txt, 01-23.txt, 01-24.txt, 01-25.txt, 01-26.txt, 01-27.txt, 01-28.txt, 01-29.txt, 01-30.txt, sample-01.txt, sample-02.txt, sample-03.txt
Case Name Status Exec Time Memory
01-01.txt 2 ms 3840 KB
01-02.txt 38 ms 7808 KB
01-03.txt 72 ms 8192 KB
01-04.txt 21 ms 10240 KB
01-05.txt 13 ms 8960 KB
01-06.txt 17 ms 9344 KB
01-07.txt 16 ms 8192 KB
01-08.txt 16 ms 8064 KB
01-09.txt 19 ms 7936 KB
01-10.txt 44 ms 7936 KB
01-11.txt 61 ms 7808 KB
01-12.txt 73 ms 7808 KB
01-13.txt 73 ms 7936 KB
01-14.txt 71 ms 7808 KB
01-15.txt 74 ms 7808 KB
01-16.txt 72 ms 7808 KB
01-17.txt 71 ms 7936 KB
01-18.txt 56 ms 7808 KB
01-19.txt 15 ms 8192 KB
01-20.txt 18 ms 7808 KB
01-21.txt 34 ms 7808 KB
01-22.txt 59 ms 7808 KB
01-23.txt 59 ms 7808 KB
01-24.txt 14 ms 7808 KB
01-25.txt 73 ms 7808 KB
01-26.txt 19 ms 7808 KB
01-27.txt 22 ms 7808 KB
01-28.txt 48 ms 7808 KB
01-29.txt 60 ms 7808 KB
01-30.txt 72 ms 7808 KB
sample-01.txt 2 ms 3840 KB
sample-02.txt 2 ms 3712 KB
sample-03.txt 2 ms 3712 KB