离散化

离散化

1.

#include <iostream>
#include <algorithm>
using namespace std;

const int MAXN = 1005;
int n;
int rev[MAXN], a[MAXN];

int main() {
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> a[i], rev[i] = a[i];
	sort(rev + 1, rev + 1 + n);
	int len = unique(rev + 1, rev + 1 + n) - rev - 1;
	for(int i = 1; i <= n; i++) {
		a[i] = lower_bound(rev + 1, rev + 1 + len, a[i]) - rev;
	}
	return 0;
}

2.

#include <iostream>
#include <algorithm>
using namespace std;

const int MAXN = 1e5;
int n, b[MAXN];

struct node {
	int val, index;
}a[MAXN];

int main() {
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> a[i].val, a[i].index = i;
	sort(a + 1, a + 1 + n, cmp);
	
	int sum = 0;
	for(int i = 1; i <= n; i++) {
		if(a[i].val != a[i - 1].val || i == 1) {
			b[a[i].index] = ++sum;
		}
		else {
			b[a[i].index] = sum;
		}
	}
	return 0;
}

3.

int Find (int x) {
	return lower_bound (v.begin (), v.end (), x) - v.begin ();
}
sort (v.begin (), v.end ());
v.erase (unique (v.begin (), v.end ()), v.end ());