Submission #4015248

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Source Code Expand

#include <bits/stdc++.h>
#define MAX_N 100000
#define INF 0x3f3f3f3f
using namespace std;
template <class T> inline void read(T &x) {
	x = 0; int c = getchar(), f = 1;
	for (; !isdigit(c); c = getchar()) if (c == 45) f = -1;
	for (; isdigit(c); c = getchar()) (x *= 10) += f*(c-48);
}
int n, rt, tot, mx; bool mrk[MAX_N+5];
int c[MAX_N+5], d[MAX_N+5], f[MAX_N+5];
char s[MAX_N+5]; vector <int> G[MAX_N+5];
void DFS(int u, int fa) {
	mrk[u] = c[u];
	for (int v : G[u]) if (v ^ fa)
		DFS(v, u), mrk[u] |= mrk[v], 
		d[u] += mrk[v], d[v] += mrk[v];
}
void DP(int u, int fa) {
	int w = ((d[u]&1)^c[u]) ? 2 : 0;
	f[u] = w, tot += d[u]+((d[u]&1)^c[u]);
	for (int v : G[u]) if ((v ^ fa) && mrk[v])
		DP(v, u), mx = max(mx, f[u]+f[v]), f[u] = max(f[u], f[v]+w);
}
int main() {
	read(n);
	for (int i = 1, u, v; i < n; i++)
		read(u), read(v), G[u].push_back(v), G[v].push_back(u);
	scanf("%s", s+1);
	for (int i = 1; i <= n; i++) c[i] = s[i] == 'W';
	for (int i = 1; !rt && i <= n; i++) if (c[i]) rt = i;
	return DFS(rt, 0), DP(rt, 0), printf("%d\n", tot-mx), 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:29:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", s+1);
                  ^

Judge Result