Sponsors

Codeforces Round #429 (Div. 2), problem: (D) Leha and another game about graph Solution In C/C++

#include<cstdio>
using namespace std;
const int MAXN = 300000+5;
const int MAXE = MAXN*2;
int to[MAXE], nxt[MAXE], head[MAXN], ne;
void addEdge(int f, int t) {
to[++ne] = t;
nxt[ne] = head[f];
head[f] = ne;
}
int n, m;
int d[MAXN];
bool vis[MAXN];
bool mark[MAXE];
int ednum;
int dfs(int u) {
vis[u] = true;
int tot = (d[u] == 1);
for (int i = head[u]; i; i = nxt[i])
{
if (vis[to[i]]) continue;
int v = to[i];
int tmp = dfs(v);
if (tmp & 1) mark[(i+1)>>1] = true, ednum ++;
tot += tmp;
}
return tot;
}
int main()
{
scanf(“%d%d”, &n, &m);
int num = 0;
for (int i = 1; i<=n; i++)
{
scanf(“%d”, &d[i]);
if (d[i] == 1) num++;
}
bool flag = false;
if (num & 1) {
for (int i = 1; i<=n; i++) {
if (d[i] == -1 && !flag) {
d[i] = 1; flag = true;
}else if (d[i] == -1) d[i] = 0;
}
if (!flag) {
puts(“-1”);
return 0;
}
}else {
for (int i = 1; i<=n; i++) if (d[i] == -1) d[i] = 0;
}
for (int i = 1; i<=m; i++) {
int u, v; scanf(“%d%d”, &u, &v);
addEdge(u, v); addEdge(v, u);
}
dfs(1);
printf(“%d\n”, ednum);
for (int i = 1; i <= m; i++) {
if (mark[i]) printf(“%d\n”, i);
}
return 0;
}

One to watch: Macquarie...

Macquarie Predicts Double-Digit Returns for ASX Healthcare Stock Macquarie Group,...

THE FREEPER CANTEEN –...

The Freeper Canteen: A Look That Up, It Must...

215% PENGU Rally Incoming?...

215% PENGU Rally Incoming? Analyst Predicts Imminent Breakout The cryptocurrency...

Junk is the new...

Junk is the New Punk: Why We're Falling Back...

Are weighted vests good...

Unlocking the Power of AI-Generated Content for SEO In today's...

Are weighted vests good...

Unlocking the Power of AI-Generated Content: A Boon or...

One to watch: Macquarie tips double-digit returns for this ASX healthcare stock

Macquarie Predicts Double-Digit Returns for ASX Healthcare Stock Macquarie Group, a prominent Australian financial services company, has issued a bullish prediction for a specific ASX-listed...

THE FREEPER CANTEEN – The Look That Up, It Must Be On My Bucket List Quiz – Wednesday, August 27, 2025

The Freeper Canteen: A Look That Up, It Must Be On My Bucket List The Freeper Canteen, a unique online community, has recently launched a...

215% PENGU Rally Incoming? Analyst Says Token ‘Inches’ From Next Leg Up

215% PENGU Rally Incoming? Analyst Predicts Imminent Breakout The cryptocurrency market is constantly fluctuating, and predicting the next big move is a challenge. However, one...

Junk is the new punk: Why we’re falling back in love with retro tech

Junk is the New Punk: Why We're Falling Back in Love with Retro Tech In a world dominated by sleek, minimalist designs and cutting-edge technology,...

Are weighted vests good for bones and muscle? Fact-checking a fitness trend – NPR

Unlocking the Power of AI-Generated Content for SEO In today's digital landscape, search engine optimization (SEO) is paramount for online success. But creating high-quality,...

Are weighted vests good for bones and muscle? Fact-checking a fitness trend – NPR

Unlocking the Power of AI-Generated Content: A Boon or Bane for SEO? The world of search engine optimization (SEO) is constantly evolving, and the recent...

TSMC cuts Chinese tools from cutting-edge chip production to avoid US ire – Nikkei Asia

TSMC Ditches Chinese Tools for Cutting-Edge Chip Production Taiwan Semiconductor Manufacturing Company (TSMC), the world's leading chipmaker, is reportedly phasing out Chinese-made equipment from its...

Google Messages beta rolling out QR code key verification – 9to5Google

Google Messages Adds QR Code Key Verification for Enhanced Security Google is bolstering the security of its Messages app with a new feature rolling out...

A Secretive US Space Plane Will Soon Test Quantum Navigation Technology

## US Space Plane to Test Revolutionary Quantum Navigation Technology The United States is on the cusp of a significant leap forward in space navigation....