Submission #2711884

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Source Code Expand

#include <bits/stdc++.h>
#define F(i,a,b) for(int i=(a);i<=(b);++i)
#define F_(i,a,b) for(int i=(a);i>=(b);--i)
#define G(i,u) for(int i=head[u];i;i=nxt[i])

typedef long long ll;

const int N = 100005;

template<typename T> inline T min(T& a, T b) {return a<b?a:a=b;}

int head[N], to[N<<1], nxt[N<<1], a[N], b[N], r[N], g[N], son[N], ecnt;
void add(int u, int v) { to[++ecnt] = v; nxt[ecnt] = head[u]; head[u] = ecnt; }
bool cmp(const int& x, const int& y) { return a[x] < a[y]; }
int find(int x) { return g[x] == x? x: g[x] = find(g[x]); }
ll f[N], sum[N];
int main() {
	#ifndef ONLINE_JUDGE
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w", stdout);
	#endif
	int n, m;
	scanf("%d%d", &n, &m);
	F(i,1,n) {
		scanf("%d%d", &a[i], &b[i]);
		a[i] = std::max(a[i]-b[i],0); 
		r[i] = i;
	}
	F(i,1,m) {
		int u, v;
		scanf("%d%d", &u, &v);
		add(u,v); add(v,u);
	}
	std::sort(r+1,r+n+1,cmp);
	F(i,1,n) {
		int x = r[i], tot = 0; g[x] = x; sum[x] = b[x];
		G(j,x) {
			int v = to[j], p = find(v);
			if(!p || p == x) continue;
			son[++tot] = p;
			sum[x] += sum[p];
			g[p] = x;
		}
		f[x] = a[x] + sum[x];
		F(j,1,tot) min(f[x],sum[x]-sum[son[j]]+std::max(f[son[j]],1ll*a[x]));
	}
	printf("%lld\n", f[r[n]]);
	return 0;
} 

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:19:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("in.txt", "r", stdin);
                               ^
./Main.cpp:20:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("out.txt", "w", stdout);
                                 ^
./Main.cpp:23:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
./Main.cpp:25:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a[i], &b[i]);
                              ^
./Main.cpp:31:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused...

Judge Result