######################################警告:此答案仅归ACGO官方所有,勿抄!(bushi)##################################################
1.
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6.```
cpp
#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;
int main() {
int n;
cin >> n;
vector<vector<int>> matrix(n + 1, vector<int>(n + 1));
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
cin >> matrix[i][j];
}
}
vector<vector<int>> row_prefix(n + 1, vector<int>(n + 1));
for (int i = 1; i <= n; ++i) {
row_prefix[i][0] = 0;
for (int j = 1; j <= n; ++j) {
row_prefix[i][j] = row_prefix[i][j - 1] + matrix[i][j];
}
}
}