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dft.cpp
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111 lines (104 loc) · 2.64 KB
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/*
* Author:heroming
* File:dft.cpp
* Time:2016/07/15 12:23:09
*/
#include <vector>
#include <list>
#include <set>
#include <map>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <string>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <ctime>
using namespace std;
#define px first
#define py second
#define pb push_back
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
#define clr(v, e) memset(v, e, sizeof(v))
#define rep(it, v) for (auto it : v)
#define forn(i, n) for (int i = 0; i < (n); ++ i)
#define form(i, a, b) for (int i = (a); i <= (b); ++ i)
#define forv(i, v) for (int i = 0; i < sz(v); ++ i)
#define iter(it, v) for (auto it = v.begin(); it != v.end(); ++ it)
typedef long long lint;
typedef vector<int> vint;
typedef vector<string> vstring;
typedef pair<int, int> pint;
typedef vector<lint> vlint;
typedef vector<pint> vpint;
const int maxn = 64;
const double pi = acos(-1.0);
const double e = 2.0 * pi / maxn;
double v[maxn];
double a[maxn], b[maxn];
double x[maxn], y[maxn];
void dft() {
for (int k = 0; k < maxn; ++ k) {
x[k] = y[k] = 0.0;
for (int i = 0; i < maxn; ++ i) {
double l_cos = cos(e * k * i);
double l_sin = sin(e * k * i);
x[k] += v[i] * l_cos;
y[k] -= v[i] * l_sin;
}
}
}
void idft() {
for (int k = 0; k < maxn; ++ k) {
a[k] = b[k] = 0.0;
for (int i = 0; i < maxn; ++ i) {
double l_cos = cos(e * k * i);
double l_sin = sin(e * k * i);
a[k] += x[i] * l_cos - y[i] * l_sin;
b[k] += x[i] * l_sin + y[i] * l_cos;
}
a[k] /= maxn;
}
}
int main() {
freopen("data.in", "r", stdin);
freopen("data.dat", "w", stdout);
for (int i = 0; i < maxn; ++ i) {
scanf("%lf", &v[i]);
}
dft();
const double threshold = 2000.0;
int cnt = 0;
for (int i = 0; i < maxn; ++ i) {
double fre = sqrt(x[i] * x[i] + y[i] * y[i]);
printf("%.6lf\n", fre < threshold ? 0.0 : 500);
if (fre < threshold) {
++ cnt;
x[i] = y[i] = 0.0;
}
}
idft();
freopen("data.out", "w", stdout);
for (int i = 0; i < maxn; ++ i) {
printf("%.6lf\n", a[i]);
}
freopen("/dev/tty", "w", stdout);
double sum = 0.0, dif = 0.0;
for (int i = 0; i < maxn; ++ i) {
sum += v[i];
dif += abs(v[i] - a[i]);
}
printf("%d : %.2lf\n", cnt, dif / sum * 100.0);
return 0;
}