Segment Tree

SegmentTree/P3264-Balanced Lineup.cpp

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+// P3264-Balanced Lineup.cpp : 定义控制台应用程序的入口点。
+//This problem is TLE if using cin and cout, but ac while changing to scanf and printf.
+
+#include "stdafx.h"
+#include <stdio.h>
+
+#define N 50005
+#define Q 200005
+
+int n, q;
+int a[N], mini[4 * N], maxi[4 * N];
+
+void init(int node, int l, int r) {
+	if(l == r) {
+		mini[node] = l;
+		maxi[node] = l;
+	} else {
+		init(2 * node, l, (l + r)/2);
+		init(2 * node + 1, (l + r)/2 + 1, r);
+
+		if(a[mini[2 * node]] <= a[mini[2 * node + 1]])
+			mini[node] = mini[2 * node];
+		else 
+			mini[node] = mini[2 * node + 1];
+
+		if(a[maxi[2 * node]] >= a[maxi[2 * node + 1]])
+			maxi[node] = maxi[2 * node];
+		else 
+			maxi[node] = maxi[2 * node + 1];
+	}
+}
+
+int minquery(int node, int l, int r, int i, int j){
+	int p1, p2;
+	if(i > r || j < l)
+		return -1;
+
+	if(l >= i && r <= j)
+		return mini[node];
+
+	p1 = minquery(2 * node, l, (l + r)/2, i, j);
+	p2 = minquery(2 *  node + 1, (l + r)/2 + 1, r, i, j);
+
+	if(p1 == -1)
+		return p2;
+	if(p2 == -1)
+		return p1;
+	if(a[p1] <= a[p2])
+		return p1;
+	return p2; 
+}
+
+int maxquery(int node, int l, int r, int i, int j){
+	int p1, p2;
+	if(i > r || j < l)
+		return -1;
+
+	if(l >= i && r <= j)
+		return maxi[node];
+
+	p1 = maxquery(2 * node, l, (l + r)/2, i, j);
+	p2 = maxquery(2 *  node + 1, (l + r)/2 + 1, r, i, j);
+
+	if(p1 == -1)
+		return p2;
+	if(p2 == -1)
+		return  p1;
+	if(a[p1] >= a[p2])
+		return p1;
+	return p2; 
+}
+
+int _tmain(int argc, _TCHAR* argv[])
+{
+	while(scanf("%d%d", &n, &q) != EOF) {
+		for(int i = 1; i <= n; ++i)
+			scanf("%d", &a[i]);
+		init(1, 1, n);
+		for(int i = 0; i < q; ++i) {
+
+			int j, k;
+			scanf("%d%d", &j, &k);
+			printf("%d\n", a[maxquery(1, 1, n, j, k)] - a[minquery(1, 1, n, j, k)]);
+		}
+	}
+	return 0;
+}
+