2019-2020 ICPC, NERC, Southern and Volga Russian Regional Contest 11/14
A
#include B
#include C
线段树维护左端点的答案就行。
#include D
E
来自coming的补题，2-sat一下
F
#include G
无脑DP，注意边界x
#include H
#include I
J
#include K
L
#include M
倍增一下，每次搞方案就行
#include N
虽然确实很傻逼但是有坑（，不能随便把一个连通块的某条边改过去，因为有可能不小心改了桥边x
#include
for (int i = 1; i < n; ++i)
if (vis[i] >= 1 && ind[i] == 1 && blks[vis[i]].idx == -2) {
//fprintf(stderr, ">2 %d %d\n", eind[i], i);
blks[vis[i]] = { eind[i], i, ifst };
}
auto ret = std::vector<Ans>();
for (auto &c: blks)
if (c.idx != -1)
ret.push_back(c);
return ret;
}
};
int main () {
int t;
scanf("%d", &t);
while (t--) {
int m;
scanf("%d", &m);
auto hm = std::vector<int>();
auto es = std::vector<std::pair<int, int>>(m);
for (auto &e: es) {
scanf("%d%d", &e.first, &e.second);
hm.push_back(e.first);
hm.push_back(e.second);
}
std::sort(hm.begin(), hm.end());
hm.erase(std::unique(hm.begin(), hm.end()), hm.end());
auto g = Graph(hm.size());
for (int i = 0; i < (int)es.size(); ++i) {
int a = std::lower_bound(hm.begin(), hm.end(), es[i].first) - hm.begin();
int b = std::lower_bound(hm.begin(), hm.end(), es[i].second) - hm.begin();
g.adde(i, a, b);
g.adde(i, b, a);
}
auto ans = g.solve();
printf("%d\n", (int)ans.size());
for (auto &c: ans) {
int a = hm[c.from], b = hm[c.to];
printf("%d %d %d\n", c.idx + 1, a, b);
}
}
return 0;
}